FA All Modules
FA All Modules
FINANCIAL ANALYTICS
Curated by Kiran Kumar K V
Content Structure
(Form 8-K), contain detailed financial and operational information, providing investors and
analysts with valuable insights into corporate performance and governance.
Alternative Data Sources
With advancements in technology and data analytics, alternative data sources have become
increasingly valuable for financial analysis. These sources include satellite imagery, social
media sentiment, web scraping, sensor data, and other non-traditional datasets that offer
unique perspectives and predictive insights into market trends, consumer behavior, and
industry dynamics.
Credit Ratings and Research Reports
Credit rating agencies, such as Moody's, Standard & Poor's, and Fitch Ratings, provide credit
ratings and research reports on issuers of debt securities, including corporations,
governments, and financial institutions. These reports assess credit risk, financial stability, and
the likelihood of default, aiding investors in evaluating creditworthiness and making
investment decisions.
Central Bank Data
Central banks, such as the Federal Reserve in the United States, the European Central Bank
(ECB), and the Bank of Japan (BOJ), release a wide range of economic and financial data,
including interest rates, monetary policy decisions, foreign exchange reserves, and money
supply statistics. Analysts closely monitor central bank data for insights into monetary policy
trends and their implications for financial markets.
Third-Party Data Providers
Various third-party data providers offer specialized financial datasets, analytical tools, and
research reports to support investment analysis, risk management, and decision-making.
These providers aggregate and deliver data from multiple sources, offering convenience,
accuracy, and timeliness to financial professionals.
Face Value - The nominal value of the bond, which represents the amount repaid to
bondholders at maturity.
Issuer - The entity or organization that issues the bond and is responsible for making
interest payments and repaying the principal amount.
Credit Rating - A measure of the issuer's creditworthiness, assigned by credit rating
agencies based on financial strength, repayment ability, and default risk.
Yield - The effective annual rate of return earned by bondholders, taking into account
the bond's price, coupon payments, and time to maturity.
Types of Bonds - Bonds come in various types, including government bonds,
corporate bonds, municipal bonds, and convertible bonds, each with its own risk-
return profile and characteristics.
Bonds offer several advantages to investors, including fixed income streams, capital
preservation, portfolio diversification, and potential tax benefits. They are commonly used by
investors seeking steady income, capital preservation, and risk mitigation in their investment
portfolios.
Stocks
Stocks, also known as equities or shares, represent ownership stakes in a company. When an
individual purchases stocks of a company, they become a shareholder, entitling them to a
portion of the company's assets and earnings.
Key features of stocks
Ownership Stake - Owning stocks gives investors a proportional ownership interest
in the company, including rights to vote on corporate matters and receive dividends.
Dividends - Some companies distribute a portion of their profits to shareholders in
the form of dividends. Dividend payments provide investors with regular income and
can enhance the total return on investment.
Price Appreciation - Stock prices fluctuate based on market demand, company
performance, economic conditions, and other factors. Investors may profit from price
appreciation by selling stocks at a higher price than their purchase price.
Liquidity - Stocks are highly liquid investments, as they can be easily bought or sold
on stock exchanges during trading hours. Liquidity facilitates efficient price discovery
and enables investors to enter or exit positions quickly.
Risk and Return - Investing in stocks entails both risks and potential rewards. While
stocks offer the potential for significant capital gains and long-term wealth
accumulation, they are also subject to market volatility, economic downturns, and
company-specific risks.
Types of Stocks - Stocks can be categorized into various types, including common
stocks, preferred stocks, growth stocks, value stocks, blue-chip stocks, and small-cap
or large-cap stocks, each with distinct characteristics and investment objectives.
Market Indices - Stock market indices, such as the S&P 500, Dow Jones Industrial
Average, and NASDAQ Composite, track the performance of groups of stocks
REITs are investment vehicles that own, operate, or finance income-generating real estate
properties. REITs allow investors to invest in real estate assets without directly owning
properties, offering diversification, income, and potential capital appreciation.
Commodities
Commodities are physical goods such as gold, silver, oil, agricultural products, and metals,
traded on commodity exchanges. Investors can gain exposure to commodities through
futures contracts, ETFs, or commodity-linked derivatives. Commodities provide diversification
and serve as inflation hedges in investment portfolios.
Foreign Exchange (Forex)
Forex markets facilitate the trading of currencies, where participants buy and sell one currency
against another. Forex trading allows investors to speculate on exchange rate movements,
hedge currency risk, and participate in international trade and investment opportunities.
Structured Products
Structured products are hybrid securities created by bundling traditional securities with
derivative components. These products offer customized risk-return profiles tailored to
specific investor preferences, such as principal protection, enhanced returns, or downside risk
mitigation.
Fixed-Income Securities (e.g., Treasury Bills, Notes, Commercial Paper)
Apart from traditional bonds, fixed-income securities encompass various debt instruments
issued by governments, corporations, and financial institutions. These securities include
Treasury bills, Treasury notes, corporate bonds, municipal bonds, and commercial paper,
offering investors income streams and capital preservation.
Securities Data Cleansing
Data cleansing is a critical prerequisite for accurate and reliable financial analysis, enabling
analysts to derive meaningful insights and make informed decisions from financial datasets.
By applying appropriate cleansing techniques tailored to specific financial instruments,
analysts can enhance the quality and usability of financial data for analytical purposes.
Here's an overview of data cleansing techniques specific to these instruments:
Data Cleansing related to Bond Historical Prices & Volume
Normalization of Data
Bond data often comes in various formats and conventions, including different coupon
frequencies, maturity dates, and yield calculation methods. Normalizing bond data
involves standardizing these variables to ensure consistency and comparability across
different bond issues.
Handling Missing Values
Bond datasets may contain missing values for key variables such as coupon rates,
yields, and maturity dates. Imputation techniques, such as mean substitution or
interpolation, can be used to estimate missing values based on available data and
underlying bond characteristics.
Validation of Bond Characteristics
Validating bond characteristics, such as issuer information, credit ratings, and bond
types, is essential for ensuring data accuracy and reliability. Cross-referencing bond
data with reputable sources, such as bond registries and credit rating agencies, helps
identify discrepancies and errors that require correction.
Yield Curve Smoothing
Yield curve data, which represents the relationship between bond yields and maturities,
often exhibits noise and irregularities due to market volatility and liquidity constraints.
Smoothing techniques, such as polynomial regression or moving averages, can be
applied to yield curve data to remove noise and enhance its interpretability for analysis.
Data Cleansing related to Stock Historical Prices & Volume
Adjustment for Corporate Actions
Stock data must be adjusted to account for corporate actions, such as stock splits,
dividends, and mergers/acquisitions, which can distort historical price and volume
data. Adjusting for corporate actions ensures the continuity and accuracy of stock price
series over time.
Identification and Removal of Outliers
Stock datasets may contain outliers, anomalous data points that deviate significantly
from the overall pattern, which can skew statistical analyses and modeling outcomes.
Outliers should be identified and removed or treated appropriately to prevent their
undue influence on analytical results.
Volume and Liquidity Filtering
Filtering stock data based on trading volume and liquidity criteria helps eliminate
illiquid stocks and low-volume trades, which may introduce noise and distortions into
the analysis. Focusing on stocks with sufficient trading activity improves the reliability
and robustness of analytical insights.
Data Cleansing related to Other Security Historical Prices & Volume
Consolidation of Security Data
Securities data often includes information on various financial instruments, such as
equities, bonds, options, and derivatives, from multiple sources and formats.
Consolidating security data involves integrating disparate datasets into a unified
format for analysis, facilitating cross-asset comparisons and portfolio management.
Validation of Security Identifiers
Validating security identifiers, such as ISINs (International Securities Identification
Numbers) and CUSIPs (Committee on Uniform Securities Identification Procedures), is
essential for accurately identifying and tracking individual securities within a dataset.
Ensuring the correctness and uniqueness of security identifiers minimizes errors in data
analysis and reporting.
Classification and Tagging of Securities
Classifying and tagging securities based on asset classes, sectors, and geographic
regions enhances data organization and facilitates portfolio analysis and risk
management. Utilizing standardized classification schemes, such as industry
classifications (e.g., GICS) and geographical regions (e.g., MSCI country indices),
improves the consistency and usability of security data.
~~~~~~~~~
FINANCIAL ANALYTICS
Curated by Kiran Kumar K V
Content Structure
# Step 1: Get historical price data for NIFTY index (^NSEI) from Yahoo Finance
ticker = '^NSEI' # Ticker symbol for NIFTY index
start_date = '2023-01-01'
end_date = '2024-01-01'
nifty_data = yf.download(ticker, start=start_date, end=end_date)
Pair Plot
A pair plot is a grid of scatterplots illustrating the relationships between pairs of variables in
a dataset. In financial analysis, pair plots can be useful for exploring correlations between
multiple financial instruments, such as stocks, bonds, or currencies. They help identify patterns
and dependencies between variables.
Distribution Plot:
A dist plot, or distribution plot, displays the distribution of a single variable's values. It
provides insights into the central tendency, spread, and shape of the data distribution. In
finance, dist plots can be used to visualize the distribution of returns, yields, or other financial
metrics, helping analysts assess risk and uncertainty.
Heatmap
A heatmap is a graphical representation of data where values in a matrix are represented as
colors. In financial analysis, heatmaps are often used to visualize correlations between
multiple variables, such as stock returns, sector performance, or asset class correlations.
Heatmaps help identify clusters, trends, and relationships in complex datasets.
Moving Average Convergence Divergence (MACD) Plots - MACD plots are used to
visualize the convergence and divergence of moving averages, indicating potential
shifts in momentum or trend direction.
Bollinger Bands - Bollinger Bands are volatility bands plotted above and below a
moving average, representing price volatility and potential reversal points in the
market.
Relative Strength Index (RSI) Plots - RSI plots display the relative strength index of
a security, indicating overbought or oversold conditions in the market.
In financial data, the sample mean offers insights into the average value of variables such as
stock prices, returns, or revenues over a specific period. For instance, calculating the average
daily closing price of a stock over a month facilitates understanding its typical value during
that period.
On the other hand, the standard deviation quantifies the dispersion or spread of data points
around the mean. It is calculated as the square root of the average of the squared differences
between each data point and the sample mean.
In finance, standard deviation serves as a crucial metric for assessing the volatility or risk
associated with a financial variable. A higher standard deviation implies greater variability or
risk, making it essential for risk management and investment decision-making. For instance,
analyzing the volatility of stock returns over a specific period aids investors in gauging the
potential risks of their investments.
Moreover, variance, the square of the standard deviation, represents the average squared
deviation from the mean. It provides a measure of the overall dispersion of data points in a
dataset and complements the standard deviation in assessing variability. By calculating the
variance, investors gain further insights into the variability of financial variables, facilitating
more informed decision-making processes. For example, evaluating the variability in the
monthly returns of an investment portfolio assists investors in understanding the level of risk
associated with their investment strategies.
Negative Skew (Left Skew) - If the distribution of data points is skewed to the left, it
means that the tail on the left side of the distribution is longer or fatter than the right
side. In financial terms, negative skewness implies that there is a higher probability of
extreme negative returns.
Positive Skew (Right Skew) - If the distribution of data points is skewed to the right,
it means that the tail on the right side of the distribution is longer or fatter than the
left side. In financial terms, positive skewness implies that there is a higher probability
of extreme positive returns.
Skewness can provide insights into the risk and return characteristics of financial assets. For
example, investors may prefer assets with positive skewness as they offer the potential for
higher returns, while negative skewness may indicate higher downside risk.
Kurtosis measures the "tailedness" or peakedness of the distribution of data points relative
to a normal distribution. It indicates whether the distribution is more or less peaked than a
normal distribution.
Leptokurtic (High Kurtosis) - If the distribution has a high kurtosis, it means that the
tails of the distribution are heavier than those of a normal distribution. Financial data
with high kurtosis tends to have fat tails, indicating a higher probability of extreme
returns (both positive and negative).
Mesokurtic (Normal Kurtosis) - If the distribution has a kurtosis equal to that of a
normal distribution (typically 3), it is considered mesokurtic. Financial data with normal
kurtosis follows a bell-shaped curve similar to a normal distribution.
Platykurtic (Low Kurtosis) - If the distribution has a low kurtosis, it means that the
tails of the distribution are lighter than those of a normal distribution. Financial data
with low kurtosis tends to have thinner tails, indicating a lower probability of extreme
returns.
Kurtosis provides insights into the volatility and risk associated with financial assets. Assets
with high kurtosis may experience more extreme price movements, while assets with low
kurtosis may exhibit more stable price behavior.
Sample correlation measures the strength and direction of the linear relationship between
two sets of returns, but it is normalized to the range [-1, 1]. It provides a standardized measure
of how much two stocks move together relative to their individual volatilities. A correlation
of 1 indicates a perfect positive linear relationship, -1 indicates a perfect negative linear
relationship, and 0 indicates no linear relationship.
A positive covariance or correlation indicates that the returns of the two stocks tend
to move in the same direction.
A negative covariance or correlation indicates that the returns of the two stocks tend
to move in opposite directions.
A covariance of zero does not necessarily imply independence; it only indicates no
linear relationship. Similarly, a correlation of zero does not imply independence, as
there may be nonlinear relationships.
Sample covariance and correlation are essential tools in portfolio management, risk
assessment, and asset allocation. Investors use covariance and correlation to diversify their
portfolios effectively, as assets with low or negative correlations can help reduce overall
portfolio risk. Additionally, understanding the covariance and correlation between assets is
crucial for risk management and constructing optimal investment portfolios.
5. Financial Returns
Financial returns are essential metrics used in finance to evaluate the performance of
investments over time. They provide insights into the profitability and efficiency of investment
decisions. In this note, we'll cover three key concepts related to financial returns - Holding
Period Return (HPR), Arithmetic Average Return, and Compound Annual Growth Rate (CAGR).
1. Holding Period Return (HPR)
Holding Period Return, also known as HPR or total return, measures the return on an
investment over a specific period, considering both capital gains (or losses) and income (such
as dividends or interest). It is expressed as a percentage and is calculated using the formula:
Systematic Risk and Beta - Systematic risk refers to the portion of an asset's risk that cannot
be diversified away. Beta measures an asset's sensitivity to market movements. A beta of 1
implies that the asset moves in tandem with the market, while a beta greater than 1 indicates
higher volatility, and a beta less than 1 suggests lower volatility compared to the market.
Expected Return Calculation - CAPM uses the following formula to estimate the expected
return (E(Ri)) of an asset i:
Market Risk Premium - The term E(Rm)−Rf denotes the market risk premium, representing
the excess return expected from investing in the market portfolio compared to a risk-free
investment. It reflects the compensation investors demand for bearing systematic risk.
Applications of CAPM in Security Analysis and Investment Decisions
Cost of Capital Estimation - CAPM is utilized to determine the cost of equity, a crucial
component in calculating the weighted average cost of capital (WACC). This cost of
equity serves as a discount rate for evaluating the present value of future cash flows,
facilitating investment appraisal and capital budgeting decisions.
Stock Valuation - CAPM aids in valuing individual stocks by providing a framework
to estimate their expected returns based on their risk profiles. Investors can compare
the calculated expected return with the current market price to assess whether a stock
is undervalued or overvalued, guiding buy or sell decisions.
Portfolio Management - CAPM is instrumental in constructing well-diversified
portfolios that aim to maximize returns for a given level of risk. By selecting assets with
different betas, investors can optimize their portfolio's risk-return profile. CAPM also
helps in evaluating the performance of existing portfolios and making adjustments to
achieve desired risk and return targets.
Asset Allocation - Asset allocation decisions are crucial for investors in achieving their
financial objectives while managing risk. CAPM assists in determining the appropriate
mix of assets by considering their expected returns and correlations with the market.
This strategic allocation helps investors optimize their portfolios for various investment
goals, such as capital preservation, income generation, or wealth accumulation.
Risk Management - CAPM aids in identifying and assessing systematic risk, enabling
investors to hedge against adverse market movements effectively. By diversifying
across assets with low correlations and optimizing portfolio weights based on CAPM
estimates, investors can mitigate unsystematic risk and achieve a more efficient risk-
return tradeoff.
Portfolio Optimization - In portfolio theory, the normal distribution is used to model the
return distribution of individual assets and portfolios. Modern portfolio theory (MPT) relies
on the assumption of normality to estimate expected returns, variances, and covariances,
which are essential inputs for constructing efficient portfolios. By optimizing portfolio weights
based on these estimates, investors can achieve better risk-adjusted returns and diversify their
investment portfolios effectively.
Statistical Analysis - The normal distribution serves as a foundation for various statistical
techniques used in financial analytics, such as hypothesis testing, regression analysis, and
parametric modeling. By assuming normality, analysts can apply standard statistical methods
to analyze financial data and make inferences about population parameters. This allows for
rigorous testing of hypotheses and the development of robust models for forecasting and
decision-making.
The lognormal distribution is a probability distribution that is commonly used to model the
distribution of asset prices and returns in financial analytics. Unlike the normal distribution,
which is symmetric and bell-shaped, the lognormal distribution is skewed and right-skewed,
with a positive skewness. It is characterized by its properties when the logarithm of the
variable follows a normal distribution.
Properties of Lognormal Distribution
Skewness - The lognormal distribution is positively skewed, meaning that it has a long
right tail. This skewness arises because the logarithm of the variable grows
exponentially, resulting in a distribution with higher probabilities of extreme positive
values.
No Negative Values - Since the logarithm of a positive number is always non-
negative, the lognormal distribution does not allow for negative values. This property
makes it suitable for modeling variables that are inherently non-negative, such as asset
prices and returns.
Multiplicative Nature - The lognormal distribution is often used to model variables
that grow multiplicatively over time, such as stock prices or asset returns. This is
because the logarithm of the variable grows linearly over time, leading to a distribution
that captures the compounding effect of returns.
Parameters - The lognormal distribution is characterized by two parameters - the
mean (μ) and the standard deviation (σ) of the logarithm of the variable. These
parameters determine the location and spread of the distribution and are used to fit
the distribution to observed data.
Why do we use Log Returns instead of Simple Returns?
Simple Returns are PORTFOLIO ADDITIVE, but not TIME ADDITIVE
Log Returns are TIME ADDITIVE, but not PORTFOLIO ADDITIVE
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FINANCIAL ANALYTICS
Curated by Kiran Kumar K V
Content Structure
Histograms - Histograms depict the distribution of values in the time series, providing
insights into the data's central tendency and dispersion.
Autocorrelation plots - Autocorrelation measures the correlation between a time series
and a lagged version of itself. Autocorrelation plots help identify patterns such as
seasonality and cyclical behavior.
Identifying Patterns and Trends
Patterns and trends in time series data can provide valuable insights into the underlying
processes driving the data. Common patterns include:
Trend - The long-term movement or directionality of the data. Trends can be increasing,
decreasing, or stable over time.
Seasonality - Regular, periodic fluctuations in the data that occur at fixed intervals, such
as daily, weekly, or yearly patterns.
Cyclical behavior - Non-periodic fluctuations in the data that occur over longer time
frames, often associated with economic cycles or other recurring phenomena.
Irregularities - Random fluctuations or noise in the data that are not explained by trends,
seasonality, or cyclical patterns.
Seasonality - Seasonal effects refer to regular, repeating patterns in the data that occur
at fixed intervals, such as daily, weekly, or yearly cycles. Non-stationary series may exhibit
seasonality, leading to variations in mean and variance across different time periods.
Other Time-Dependent Structures - Non-stationary series may also display other time-
dependent structures, such as cyclical behavior or irregular fluctuations.
Transformations to Achieve Stationarity
When dealing with non-stationary time series data, transformations can be applied to make
the series stationary. One common transformation technique is differencing, which involves
computing the difference between consecutive observations. By removing trends and
seasonality through differencing, the resulting series may exhibit stationarity.
First-order differencing - Computes the difference between each observation and its
immediate predecessor.
Higher-order differencing - In cases of higher-order trends or seasonality, multiple
difference operations may be necessary to achieve stationarity.
Importance of Stationarity
Stationarity is important in time series analysis for several reasons:
Many statistical techniques and models assume stationarity to produce accurate results.
For example, classic time series models like ARMA (Auto-Regressive Moving Average)
require stationary data.
Stationarity simplifies the analysis by providing a stable framework for interpreting the
data and making predictions.
Stationarity allows for meaningful comparisons between different time periods and
facilitates the identification of underlying patterns and relationships within the data.
ARMA Model
Combining the autoregressive and moving average components, an ARMA(p, q) model can
be expressed as the sum of an AR(p) process and an MA(q) process:
4. Power Transformations
Power transformations are a valuable technique used in time series analysis to stabilize the
variance of a series, especially when the variance is not constant across different levels of the
mean. By transforming the data using a power function, power transformations can help
address issues such as heteroscedasticity and non-normality, making the data more amenable
to analysis and modeling.
Motivation for Power Transformations
In many time series datasets, the variability of the observations may change as the mean of
the series changes. This phenomenon, known as heteroscedasticity, violates the assumption
of constant variance required by many statistical techniques. Additionally, non-normality in
the data distribution can affect the validity of statistical tests and inference procedures. Power
Estimating λ
The choice of the power parameter λ is crucial in the Box-Cox transformation and can
significantly impact the effectiveness of the transformation. Common methods for estimating
λ include maximum likelihood estimation (MLE), which seeks to maximize the likelihood
function of the transformed data, and graphical techniques such as the profile likelihood plot
or the Box-Cox plot.
Interpretation and Application
λ > 1: Indicates a positive transformation, where the data is raised to a power greater than
1. This compresses lower values and stretches higher values, often used to stabilize
variance in data with right-skewed distributions.
λ = 1: Represents a natural logarithm transformation, useful for stabilizing variance and
approximating normality in data with exponential growth patterns.
0 < λ < 1: Indicates a fractional transformation, commonly used to stabilize variance in
data with left-skewed distributions.
Considerations and Limitations
The Box-Cox transformation assumes that the data values are strictly positive. For data
containing zero or negative values, alternative transformations may be necessary.
The choice of λ should be guided by both statistical considerations and domain
knowledge, as overly aggressive transformations can distort the interpretation of the data.
The effectiveness of the transformation should be assessed through diagnostic checks,
such as examining residual plots or conducting statistical tests for normality and
homoscedasticity.
Careful selection of model parameters is essential, as overly complex models may lead to
overfitting, while overly simple models may fail to capture important patterns in the data.
Interpretation of ARIMA model results should be done cautiously, considering the
assumptions and limitations of the model.
Python Project
Let’s create a python project that generates an ARIMA model for a security:
The Durbin-Watson Test Statistic value of 3.0786708200908914, which falls between the range
of 0 to 4, indicates the degree of autocorrelation present in the differenced data.
The Durbin-Watson test statistic ranges between 0 and 4, with a value close to 2 indicating
no autocorrelation. Values significantly below 2 indicate positive autocorrelation (i.e.,
consecutive observations are correlated), while values significantly above 2 indicate negative
autocorrelation (i.e., consecutive observations are negatively correlated).
In this case, the test statistic is close to 2, which suggests that there is little to no
autocorrelation present in the differenced data. A value of 3.0786708200908914 indicates a
mild positive autocorrelation, but it's close enough to 2 that it's often considered acceptable.
Therefore, the differenced data is likely adequately stationary for further analysis.
For the ACF (Autocorrelation Function) plot of the Price Data, the correlation lines at all lag
levels being close to 1 indicate a strong positive autocorrelation, suggesting that each
observation in the time series is highly correlated with its neighboring observations. However,
the slowly decaying nature of these correlations indicates that while there is a strong
correlation between adjacent observations, this correlation diminishes as the time lag
increases. This implies that while recent prices heavily influence each other, the influence
gradually diminishes as we move further back in time.
Regarding the PACF (Partial Autocorrelation Function) plot of the Price Data, the high values
of lag-0 and lag-1, both close to 1, suggest strong partial autocorrelation at these lags. This
indicates that each observation in the time series is significantly influenced by its immediate
predecessor and the one just before it. Additionally, all other partial autocorrelations being
close to 0 and falling within the significance range (represented by the shaded blue area)
indicate that once we account for the influence of these immediate predecessors, the
influence of other observations becomes minimal and not statistically significant. This
suggests that the current observation is predominantly influenced by its recent past, with
diminishing influence from observations further back in time.
The line plot of the stock returns illustrates a consistent level of volatility throughout the
analyzed period, characterized by fluctuations in returns around the mean. However, there
appears to be a notable increase in volatility during the initial period, marked by a spike in
the amplitude of fluctuations. This spike indicates a period of heightened variability in returns,
suggesting that significant market events or factors may have influenced stock performance
during that time.
In terms of stationarity, the visualization suggests that the data may not be entirely stationary.
Stationarity in a time series context typically refers to the statistical properties of the data
remaining constant over time, such as constant mean and variance. While the overall pattern
of returns shows relatively steady volatility, the spike in volatility during the initial period
suggests a departure from stationarity. Stationarity assumptions are crucial for many time
series analysis techniques, such as ARIMA modeling, as violations of stationarity can lead to
unreliable model results. Therefore, further investigation and potentially applying
transformations or differencing techniques may be necessary to achieve stationarity in the
data before proceeding with analysis.
The output represents the results of a stepwise search to find the best ARIMA model order
that minimizes the Akaike Information Criterion (AIC), a measure used for model selection.
Each line in the output corresponds to a different ARIMA model that was evaluated during
the search.
Here's an interpretation of the output:
ARIMA(p,d,q)(P,D,Q)[m] - This notation represents the parameters of the ARIMA model,
where 'p' denotes the number of autoregressive (AR) terms, 'd' denotes the degree of
differencing, 'q' denotes the number of moving average (MA) terms, 'P', 'D', and 'Q' denote
seasonal AR, differencing, and MA terms, respectively, and 'm' denotes the seasonal
period.
AIC - The Akaike Information Criterion is a measure of the relative quality of a statistical
model for a given set of data. Lower AIC values indicate better-fitting models.
Time - The time taken to fit the respective ARIMA model.
Best model - The ARIMA model with the lowest AIC value, which indicates the best-fitting
model according to the stepwise search.
Best ARIMA Model Order - This indicates the order of the best-fitting ARIMA model, in this
case, (4, 0, 5), suggesting that the model includes four AR terms, no differencing, and five
MA terms.
Total fit time - The total time taken for the entire stepwise search process.
In this output, the best-fitting ARIMA model order is (4, 0, 5), meaning it includes four AR
terms, no differencing, and five MA terms. This model achieved the lowest AIC value among
all the tested models, indicating its superiority in capturing the underlying patterns in the
data. However, it's essential to further evaluate the model's performance using diagnostic
checks to ensure its adequacy for forecasting purposes.
The provided output represents the results of fitting a SARIMAX (Seasonal AutoRegressive
Integrated Moving Average with eXogenous regressors) model to the data.
Here's an interpretation of the key components of the output:
Dep. Variable - This indicates the dependent variable used in the model, which in this case
is "Adj Close" representing adjusted closing prices of the stock.
No. Observations - The number of observations used in the model, which is 989.
Model - Specifies the type of model used. In this case, it's an ARIMA(4, 0, 5) model,
indicating four autoregressive (AR) terms, no differencing (d = 0), and five moving average
(MA) terms.
Log Likelihood - The log-likelihood value, which is a measure of how well the model fits
the data. Higher values indicate better fit.
AIC (Akaike Information Criterion) - A measure of the relative quality of a statistical model
for a given set of data. Lower AIC values indicate better-fitting models. In this case, the
AIC value is -5808.515.
BIC (Bayesian Information Criterion) - Similar to AIC, BIC is used for model selection. It
penalizes model complexity more strongly than AIC. Lower BIC values indicate better-
fitting models. Here, the BIC value is -5754.651.
Sample - Specifies the range of observations used in the model. In this case, it ranges from
0 to 989.
Covariance Type - Specifies the type of covariance estimator used in the model. In this
case, it's "opg" (Opeck-Gleser), which is one of the available options for estimating the
covariance matrix.
The provided output represents the coefficient estimates, standard errors, z-values, p-values,
and the confidence intervals for each coefficient in the SARIMAX model.
const - Represents the intercept term in the model. In this case, the coefficient is 1.505e-
06 with a standard error of 5.46e-05. The z-value is 0.028, and the p-value is 0.978,
indicating that the intercept term is not statistically significant at conventional levels of
significance (e.g., α = 0.05).
ar.L1, ar.L2, ar.L3, ar.L4 - These are the autoregressive (AR) terms in the model. They
represent the coefficients of the lagged values of the dependent variable. The coefficients
represent the strength and direction of the relationship between the variable and its
lagged values. All of these coefficients have p-values less than 0.05, indicating that they
are statistically significant.
ma.L1, ma.L2, ma.L3, ma.L4, ma.L5 - These are the moving average (MA) terms in the
model. They represent the coefficients of the lagged forecast errors. Similar to the AR
terms, these coefficients indicate the strength and direction of the relationship between
the forecast errors and their lagged values. Notably, ma.L2 has a p-value greater than 0.05,
suggesting that it is not statistically significant.
sigma2 - Represents the variance of the residuals (error term) in the model. It is estimated
to be 0.0002 with a high level of statistical significance.
The provided output includes diagnostic test results for the SARIMAX model, including the
Ljung-Box test, Jarque-Bera test, and tests for heteroskedasticity.
Ljung-Box (L1) (Q) - The Ljung-Box test is a statistical test that checks whether any group
of autocorrelations of a time series is different from zero. The "L1" in parentheses indicates
the lag at which the test is performed. In this case, the test statistic is 0.24, and the p-value
(Prob(Q)) is 0.63. Since the p-value is greater than the significance level (commonly 0.05),
we fail to reject the null hypothesis of no autocorrelation in the residuals at lag 1.
Jarque-Bera (JB) - The Jarque-Bera test is a goodness-of-fit test that checks whether the
data follows a normal distribution. The test statistic is 5303.06, and the p-value (Prob(JB))
is reported as 0.00. A low p-value suggests that the residuals are not normally distributed.
Heteroskedasticity (H) - Heteroskedasticity refers to the situation where the variability of a
variable is unequal across its range. The test for heteroskedasticity reports a test statistic
of 0.16 and a p-value (Prob(H)) of 0.00. A low p-value suggests that there is evidence of
heteroskedasticity in the residuals.
Skew and Kurtosis - Skewness measures the asymmetry of the distribution of the residuals,
and kurtosis measures the "tailedness" or thickness of the tails of the distribution. In this
case, skew is reported as 0.07, indicating a slight skewness, and kurtosis is reported as
14.34, indicating heavy-tailedness.
Overall, these diagnostic tests provide valuable information about the adequacy of the
SARIMAX model. While the Ljung-Box test suggests no significant autocorrelation at lag 1,
the Jarque-Bera test indicates potential non-normality in the residuals, and the test for
heteroskedasticity suggests unequal variability. These findings may warrant further
investigation or model refinement.
Predicted values
~~~~~~~~~~
FINANCIAL ANALYTICS
Curated by Kiran Kumar K V
Content Structure
If you bought a stock for Rs. 50, received Rs. 2 in dividends, and the stock price increased to
Rs. 60 during the holding period, the holding period return would be:
Suppose you have the following annual returns for a stock over a 5-year period: 10%, 5%, -
2%, 8%, and 12%. To calculate the average return, you would sum up these returns and divide
by the number of periods:
Keep in mind that these calculations provide simple measures of return and may not account
for factors such as taxes, transaction costs, or inflation. Additionally, when using price-based
returns, it's essential to adjust for stock splits, dividends, and other corporate actions that
affect the security's price.
Computing Risk Measures on a Security
To compute the variance and standard deviation of returns of a security, you'll need historical
data on the security's returns over a specific period.
1. Variance of Returns:
The variance of returns measures the dispersion or variability of the security's returns around
its mean return. It provides insights into the level of risk or volatility associated with the
security. The formula for calculating the variance of returns is:
Suppose you have the following annual returns for a security over a 5-year period: 10%, 5%,
-2%, 8%, and 12%. To calculate the variance and standard deviation of returns:
So, the variance of returns for the security is approximately 29.8% and the standard deviation
of returns is approximately 5.46%.
3. Beta of Returns:
To compute the beta of an individual security, you need historical data on the returns of the
security as well as the returns of a market index over the same time period. Beta measures
the sensitivity of a security's returns to the returns of the overall market.
Finally, calculate the beta of the security by dividing the covariance between the security and
the market index by the variance of the market returns. (Covariance of returns computation
is shown in the next section)
A beta greater than 1 indicates that the security tends to be more volatile than the market,
while a beta less than 1 indicates that the security tends to be less volatile than the market.
Given that the covariance and variance of market returns as below, let's compute the beta:
Covariance between Security and Market: 23.3%
Variance of Market Returns: 18.3%
2. Correlation of Returns:
Correlation measures the strength and direction of the linear relationship between the returns
of two securities. It is a standardized measure that ranges from -1 to 1, where -1 indicates a
perfect negative correlation, 0 indicates no correlation, and 1 indicates a perfect positive
correlation. The formula for calculating the correlation of returns between two securities 𝑋
and 𝑌 is:
Suppose you have the following annual returns for two securities, Security X and Security Y,
over a 5-year period:
Security X: 10%, 5%, -2%, 8%, and 12%
Security Y: 8%, 4%, -1%, 7%, and 10%
To calculate the covariance and correlation of returns between Security X and Security Y:
1. Portfolio Return
The portfolio return is the weighted average of the returns of the individual securities in the
portfolio. The formula to compute the portfolio return is:
3. Portfolio Beta
The portfolio beta measures the sensitivity of the portfolio's returns to the returns of the
market index. It is a weighted average of the betas of the individual securities in the portfolio.
The formula to compute the portfolio beta is:
Let's compute the portfolio return, standard deviation, and beta for the below example.
2. Treynor Ratio:
The Treynor ratio measures the excess return per unit of systematic risk, where systematic risk
is measured by the portfolio's beta. It's calculated as:
Jensen's alpha measures the risk-adjusted return of the portfolio after adjusting for systematic
risk. It's calculated as the difference between the actual portfolio return and the expected
return predicted by the Capital Asset Pricing Model (CAPM):
In an efficient frontier, inefficient portfolios refer to those that offer suboptimal risk-return
trade-offs compared to portfolios that lie on the frontier itself. These portfolios provide
inferior risk-return characteristics compared to portfolios on the efficient frontier. These
portfolios either offer lower expected returns for a given level of risk or higher risk for a given
level of expected return.
Inefficient Portfolios
The minimum variance portfolio represents the portfolio with the lowest level of risk or
volatility achievable within a given investment universe. It is characterized by the smallest
possible standard deviation or variance of returns among all portfolios on the efficient
frontier.
The efficient frontier represents the set of optimal portfolios that offer the highest expected
return for a given level of risk or the lowest risk for a given level of expected return. EF
illustrates the range of possible portfolios that maximize returns for a given level of risk, or
minimize risk for a given level of return.
Characteristics
Convex Shape - The efficient frontier typically exhibits a convex shape, indicating that as
an investor seeks higher expected returns, they must accept increasing levels of risk.
Optimal Portfolios - Portfolios lying on the efficient frontier are considered optimal
because they offer the best risk-return trade-offs available within the investment universe.
Diversification - The efficient frontier underscores the importance of diversification in
portfolio construction. By combining assets with different risk-return profiles, investors
can achieve portfolios that lie on or close to the efficient frontier, thereby maximizing
returns while minimizing risk.
Efficient Frontier
Multi-Objective Optimization
Extend portfolio optimization to consider multiple conflicting objectives simultaneously, such
as maximizing returns, minimizing risk, and achieving specific constraints. Employ multi-
objective optimization algorithms to identify Pareto-optimal solutions that represent trade-
offs between competing objectives.
Hierarchical Risk Parity (HRP)
Apply hierarchical clustering techniques to group assets into clusters based on their pairwise
correlations. Construct portfolios using the HRP framework, which allocates weights to
clusters rather than individual assets, promoting diversification and stability across different
market regimes.
Machine Learning-based Portfolio Construction
Leverage machine learning algorithms, such as neural networks, random forests, or deep
learning models, to extract complex patterns from historical data and generate optimized
portfolios. Explore techniques like reinforcement learning for portfolio allocation in dynamic
and non-linear environments.
Integration of Alternative Assets
Extend portfolio optimization to include alternative assets classes such as private equity,
hedge funds, real estate, or commodities. Develop custom optimization models that account
for illiquidity, non-normal return distributions, and unique risk factors associated with
alternative investments.
Economic Scenario Generation
Generate a comprehensive set of economic scenarios using Monte Carlo simulations,
historical bootstrapping, or scenario-based modeling techniques. Optimize portfolios to
perform well across a wide range of economic scenarios, including stress testing and scenario
analysis.
risk in exchange for the possibility of higher returns. They may prefer portfolios with higher
expected returns, even if they come with greater volatility.
Portfolio optimization involves selecting the portfolio that maximizes the investor's utility
function. This typically involves solving an optimization problem that considers the trade-off
between risk and return while taking into account the investor's utility function and
constraints such as budget constraints, asset class constraints, and regulatory constraints.
Case of Building an Efficient & Optimum Portfolio using Excel
Step-1. We considered 5 stocks Apar Industries, Oil India, Apollo Tyres, Tata Chemicals &
Narayana Hrudayalaya
Step-2. Collected the below inputs:
Step-5. Using the SOLVER pack in Excel, determined the optimal weights
Repeat the same process to either maximize Treynor’s Ratio or Jensen’s Alpha
~~~~~~~~~~
FINANCIAL ANALYTICS
Curated by Kiran Kumar K V
Content Structure
Mathematical Formulation
The logistic regression model can be represented as follows:
The parameters of the logistic regression model are estimated using maximum
likelihood estimation (MLE). The objective is to maximize the likelihood of observing the given
binary outcomes (0 or 1) given the input features and the model parameters.
Model Interpretation
Coefficients Interpretation - The coefficients (𝛽 values) of the logistic regression model
represent the change in the log-odds of the outcome variable for a one-unit change
in the corresponding predictor variable, holding other variables constant.
Odds Ratio - The exponentiated coefficients (𝑒𝛽 values) represent the odds ratio, which
quantifies the change in the odds of the positive outcome for a one-unit change in the
predictor variable.
Model Evaluation
Metrics - Logistic regression models are evaluated using various metrics such as
accuracy, precision, recall, F1-score, ROC curve, and AUC-ROC (Area Under the ROC
Curve). These metrics assess the model's performance in correctly classifying instances
into the appropriate classes.
Cross-Validation - Cross-validation techniques such as k-fold cross-validation are used
to assess the generalization performance of the model and detect overfitting.
Case of Credit Default Prediction using Logistic Regression
In this project, we aim to build a credit default prediction model using logistic regression on
a dataset containing various features related to borrowers' credit behavior. The dataset
includes information such as credit utilization, age, income, past payment history, and number
of dependents. The target variable, 'SeriousDlqin2yrs', indicates whether a person
experienced a 90-day past due delinquency or worse.
Dataset Description
SeriousDlqin2yrs: Binary variable indicating whether the borrower experienced a 90-day
past due delinquency or worse (Y/N).
In this script:
Line 1-8 - Import necessary libraries/packages for data manipulation, visualization, model
building, and evaluation.
Line 11 - Read the loan dataset from a CSV file into a pandas DataFrame and display its
dimensions.
Line 13 - Group the data by the target variable ('SeriousDlqin2yrs') and display the count
of each class.
Line 16-17 - Define the independent variables (features) and dependent variable (target
variable) by splitting the dataset.
Line 20-21 - Split the data into training and test sets with 70% training data and 30% test
data.
Line 24 - Initialize the Logistic Regression model.
Line 27 - Fit the logistic regression model to the training data to estimate the coefficients.
Line 30 - Make predictions on the test data using the trained logistic regression model.
Line 33 - Generate and plot the confusion matrix to evaluate the model's performance.
Line 36-38 - Generate and print the classification report containing precision, recall, F1-
score, and support for each class.
Confusion Matrix
The confusion matrix provides a detailed breakdown of the model's predictions compared to
the actual class labels.
True Positive (TP): 41279 - The model correctly predicted 41279 instances as positive
(default) that are actually positive.
True Negative (TN): 53 - The model correctly predicted 53 instances as negative (non-
default) that are actually negative.
False Positive (FP): 35 - The model incorrectly predicted 35 instances as positive
(default) that are actually negative (non-default).
False Negative (FN): 3001 - The model incorrectly predicted 3001 instances as negative
(non-default) that are actually positive (default).
Accuracy measures the overall correctness of the model's predictions and is calculated as the
ratio of correctly predicted instances to the total number of instances.
The model achieves an accuracy of approximately 93.19%, indicating that it correctly predicts
the class labels for 93.19% of the instances in the dataset.
Precision measures the proportion of true positive predictions among all positive predictions
and is calculated as the ratio of true positives to the sum of true positives and false.
he precision is approximately 99.92%, meaning that among all instances predicted as positive
(default), almost all (99.92%) are actually positive.
Recall (Sensitivity) measures the proportion of true positive predictions among all actual
positive instances and is calculated as the ratio of true positives to the sum of true positives
and false negatives.
The recall is approximately 93.21%, indicating that the model correctly identifies around
93.21% of all actual positive (default) instances.
We can also look at the Classification Report to evaluate the model:
The classification report presents the performance metrics of a binary classification model.
Here's the interpretation:
Precision - Precision measures the proportion of true positive predictions among all
positive predictions. For class 0 (non-default), the precision is 0.93, indicating that 93% of
the instances predicted as non-default are actually non-default. For class 1 (default), the
precision is 0.60, meaning that only 60% of the instances predicted as default are actually
default.
Recall (Sensitivity) - Recall measures the proportion of true positive predictions among all
actual positive instances. For class 0, the recall is 1.00, indicating that the model correctly
identifies all non-default instances. However, for class 1, the recall is very low at 0.02,
indicating that the model misses a significant number of actual default instances.
F1-score - The F1-score is the harmonic mean of precision and recall and provides a
balance between the two metrics. For class 0, the F1-score is 0.96, reflecting a high level
of accuracy in predicting non-default instances. However, for class 1, the F1-score is only
0.03, indicating poor performance in predicting default instances.
Accuracy - Accuracy measures the overall correctness of the model's predictions. In this
case, the accuracy is 0.93, indicating that the model correctly predicts the class labels for
93% of the instances in the test dataset.
Macro Average - The macro average calculates the average of precision, recall, and F1-
score across all classes. In this case, the macro average precision is 0.77, recall is 0.51, and
F1-score is 0.50.
Weighted Average - The weighted average calculates the average of precision, recall, and
F1-score weighted by the number of instances in each class. In this case, the weighted
average precision is 0.91, recall is 0.93, and F1-score is 0.90.
Overall, the model performs well in predicting non-default instances (class 0) with high
precision, recall, and F1-score. However, it struggles to correctly identify default instances
(class 1), leading to low recall and F1-score for this class. The high accuracy is mainly driven
by the large number of non-default instances in the dataset, but the model's performance on
default instances is unsatisfactory. Further improvement is needed to enhance the model's
ability to predict default cases accurately.
Monte Carlo simulation is extensively used in finance for pricing options, simulating asset
prices, and assessing portfolio risk. It helps in understanding the potential range of returns
and the likelihood of different financial scenarios.
Case of Stock Price Prediction using Monte Carlo Simulation
Problem Statement - Predicting the future stock price of a given company using historical
price data and Monte Carlo simulation.
Steps to Follow
Step-1. Data Collection - Gather historical stock price data for the company of interest. This
data typically includes the date and closing price of the stock over a specified period.
Step-2. Calculate Returns - Compute the daily returns of the stock using the historical price
data. Daily returns are calculated as the percentage change in stock price from one
day to the next.
Step-3. Calculate Mean and Standard Deviation - Calculate the mean and standard deviation
of the daily returns. These parameters will be used to model the behavior of the
stock price.
Step-4. Generate Random Price Paths - Use Monte Carlo simulation to generate multiple
random price paths based on the calculated mean, standard deviation, and the
current stock price. Each price path represents a possible future trajectory of the
stock price.
Step-5. Analyze Results - Analyze the distribution of simulated price paths to understand
the range of potential outcomes and assess the likelihood of different scenarios.
We start by collecting historical stock price data and calculating the daily returns. Using the
daily returns, we compute the mean (mu) and standard deviation (sigma) of returns, which
serve as parameters for the Monte Carlo simulation. We specify the number of simulations
and the number of days to simulate into the future. In the Monte Carlo simulation loop, we
generate random daily returns based on a normal distribution with mean mu and standard
deviation sigma. Using these daily returns, we calculate the simulated price paths for each
simulation. Finally, we plot the simulated price paths along with the historical prices to
visualize the range of potential outcomes.
Rules - In addition to the lexicon, VADER incorporates a set of rules and heuristics to
handle sentiment in text data more accurately. These rules account for various linguistic
features such as capitalization, punctuation, degree modifiers, conjunctions, and
emoticons.
Sentiment Scores - VADER produces sentiment scores for each input text, including -
Positive Score - The proportion of words in the text that are classified as positive.
Negative Score - The proportion of words in the text that are classified as negative.
Neutral Score - The proportion of words in the text that are classified as neutral.
Compound Score - A single score that represents the overall sentiment of the text,
calculated by summing the valence scores of each word in the text, adjusted for
intensity and polarity. The compound score is a lexicon metric that calculates the
sum of all positive and negative sentiments normalized between -1(negative) to +1
(positive). If compound >0 is categorized as positive, compound<0 is categorized
as negative, and compound=0 categorized as neutral sentiments
Case of VADER Sentiment Analysis on News Headlines of a Stock
Problem Statement – Use the NewsAPI and VADER sentiment analysis tool to streamline the
process of gathering, analyzing, and visualizing sentiment from news headlines related to a
specific stock symbol.
*NewsAPI is a tool for accessing a vast array of news articles and headlines from around the
world. It provides developers with a simple and intuitive interface to search and retrieve news
content based on various criteria such as keywords, language, sources, and publication dates.
With its extensive coverage of news sources, including major publications and local news
outlets, NewsAPI offers users the ability to stay updated on the latest developments across a
wide range of topics and industries. Whether for research, analysis, or staying informed,
NewsAPI facilitates seamless access to timely and relevant news content, making it an
invaluable resource for developers, researchers, journalists, and anyone seeking access to up-
to-date news information. (https://newsapi.org/ )
Steps followed
User inputs a stock symbol of interest.
The Python script interacts with the NewsAPI to fetch top headlines related to the
specified stock symbol.
Using the VADER sentiment analysis tool, the script analyzes the sentiment of each
headline, categorizing it as positive, neutral, or negative.
The sentiment distribution among the collected headlines is visualized through a bar
chart, providing insights into market sentiment trends.
Additionally, the script generates a word cloud based on the collected headlines,
highlighting the most frequently occurring words and visualizing key themes.
Python Script
Output
These numbers represent the sentiment distribution among the analyzed headlines.
Specifically:
There were 17 headlines with a negative sentiment.
There were 40 headlines with a neutral sentiment.
There were 37 headlines with a positive sentiment.
In the histogram, the x-axis represents the range of compound scores, while the y-axis
represents the frequency or count of headlines falling within each score range. The histogram
is divided into bins, with each bin representing a range of compound scores.
When the majority of observations are around 0 on the histogram, it indicates that a
significant proportion of the analyzed headlines have a neutral sentiment. This means that
these headlines neither convey strongly positive nor strongly negative sentiment. Instead,
they are likely reporting factual information or presenting a balanced view of the topic.
In financial news analysis, it's common to observe a clustering of headlines around a neutral
sentiment, as news reporting often aims to provide objective and factual information to
investors. However, the presence of headlines with extreme positive or negative sentiment
scores can also be indicative of noteworthy developments or market sentiment shifts that
investors may find important to consider in their decision-making process.
WORDCLOUD as a Sentiment Analysis Tool
Word clouds are graphical representations of text data where the size of each word indicates
its frequency or importance within the text. Word clouds provide a visually appealing way to
identify and visualize the most frequently occurring words in a collection of text data. In
finance, this can include news headlines, financial reports, analyst opinions, or social media
chatter related to stocks, companies, or market trends.
By analyzing the words that appear most frequently in a word cloud, analysts can identify
terms that are strongly associated with positive, negative, or neutral sentiment. For example,
words like "profit," "growth," and "bullish" may indicate positive sentiment, while words like
"loss," "decline," and "bearish" may indicate negative sentiment.
The size or prominence of each word in the word cloud reflects its frequency or importance
within the text data. This allows analysts to gauge the intensity of sentiment associated with
certain terms. Larger words typically represent terms that are more prevalent or impactful in
conveying sentiment.
Word clouds provide context by displaying words in relation to one another, allowing analysts
to understand the broader context of sentiment within the text data. For example, positive
and negative terms may appear together, providing insights into nuanced sentiment or
conflicting viewpoints.
Case of WORDCLOUD generation for Sentiment Analysis on News Headlines of a Stock
Problem Statement - Generate a visual representation of the most frequently occurring words
in the collected headlines, thereby providing users with insights into prevalent themes and
sentiment trends.
Steps followed
Step-1. Prompt the user to enter a search query (e.g., stock name or topic of interest).
Step-2. Utilize the NewsAPI to fetch top headlines related to the user-entered search query.
Step-3. Extract the headlines and publication dates from the fetched news articles.
Step-4. Concatenate the extracted headlines into a single text string.
Step-5. Exclude the queried word from the text to avoid bias
Step-6. Generate a word cloud from the concatenated text using the WordCloud library.
Step-7. Display the generated word cloud as a visual representation of the most frequently
occurring words in the news headlines.
Python Script
Output
The number of times bootstrapping is performed, typically around 1,000 times, can provide
a high level of certainty about the reliability of statistics. However, bootstrapping can also be
accomplished with fewer samples, such as 50 samples. Understanding the probability of items
being chosen in random samples helps determine the size of the train and test sets, with
approximately one-third of the dataset remaining unchosen or out-of-bag.
Case of Applying Bootstrapping in Average & Standard Deviation of Stock Returns
Problem Statement - Apply bootstrapping technique to estimate the mean and standard
deviation of stock returns based on historical price data
Steps Followed
Step-1. Use the Yahoo Finance API to collect historical stock price data for a specified
number of days.
Step-2. Compute the daily returns from the collected stock price data.
Step-3. Bootstrapping - Implement the bootstrapping technique to estimate the mean and
standard deviation of returns.
Step-4. Generate multiple bootstrapped samples by resampling with replacement.
Step-5. Compute the mean and standard deviation of returns for each bootstrapped
sample.
Step-6. Present the results in a tabular format, including the stock name, period of data
collection, mean of returns, standard deviation of returns, and confidence intervals.
Step-7. Optionally, visualize the data and results using plots or charts for better
understanding.
Python Code
Output
Cross-Validation
Cross-validation is a widely used technique in machine learning and statistical modeling for
assessing the performance and generalization ability of predictive models. It is particularly
useful when dealing with a limited amount of data or when trying to avoid overfitting.
In cross-validation, the available data is split into multiple subsets or folds. The model is
trained on a subset of the data, called the training set, and then evaluated on the remaining
data, called the validation set or test set. This process is repeated multiple times, with each
subset serving as both the training and validation sets in different iterations.
The most common type of cross-validation is k-fold cross-validation, where the data is
divided into k equal-sized folds. The model is trained k times, each time using k-1 folds for
training and the remaining fold for validation. The performance metrics (e.g., accuracy, error)
obtained from each iteration are then averaged to provide a more reliable estimate of the
model's performance.
Cross-validation helps to:
Reduce Overfitting - By evaluating the model's performance on multiple subsets of data,
cross-validation provides a more accurate assessment of how well the model will
generalize to unseen data.
Utilize Data Efficiently - It allows for the maximum utilization of available data by using
each data point for both training and validation.
Tune Model Hyperparameters - Cross-validation is often used in hyperparameter tuning to
find the optimal set of hyperparameters that yield the best model performance.
There are variations of cross-validation techniques, such as stratified k-fold cross-validation
(ensuring that each fold preserves the proportion of class labels), leave-one-out cross-
validation (each data point serves as a separate validation set), and nested cross-validation
(used for model selection and hyperparameter tuning within each fold).
Steps followed
Step-1. Utilize the Yahoo Finance API to collect historical stock price data for a specified stock
symbol over a defined time period.
Step-2. Model Training and Evaluation - Implement a linear regression model to predict stock
prices based on historical data.
Step-3. Perform k-fold cross-validation to evaluate the model's predictive performance.
Step-4. Split the historical data into k subsets (folds) and train the model on k-1 subsets while
evaluating its performance on the remaining subset.
Step-5. Compute evaluation metrics (e.g., R-squared score) for each fold to assess the
model's accuracy and generalization ability.
Step-6. Results Analysis - Calculate the mean and standard deviation of evaluation metrics
(e.g., mean R-squared score) across all folds.
Step-7. Interpret the results to determine the model's predictive performance and reliability.
Python Script
Output
The R-squared score measures the proportion of the variance in the dependent variable (stock
prices) that is explained by the independent variable(s) (features used in the model). A higher
mean R-squared score (closer to 1) indicates that the model explains a larger proportion of
the variance in the target variable and is better at predicting stock prices. In this case, the
mean R-squared score of 0.75 suggests that the linear regression model performs well in
explaining the variation in stock prices, capturing about 75% of the variance in the data.
The standard deviation of the R-squared score provides information about the variability
or consistency of the model's performance across different folds. A lower standard deviation
indicates less variability in performance across folds. In this case, the standard deviation of
approximately 0.02 suggests that the model's performance is relatively consistent across
different folds.
Extract the features (independent variables) and the target variable (stock price).
Apply standard scaling to the features to normalize the data.
Split the dataset into training and testing sets.
Train a linear regression model using the training data.
Prepare data for predicting the stock price for the next 5 quarters.
Predict the stock prices for the next 5 quarters using the trained model.
Visualize historical prices and predicted prices on a line graph.
Display the graph to compare historical and predicted stock prices.
Python Code
Output (As the data is a randomly generated sample, the output looks abnormal)
~~~~~~~~~~