In 1994, online stock trading required an attached bank account or a check sent in to fund the account, which would take days. The boys in the dorm do neither of these things and just start trading instantly. UPDATE: However, two of the boys had already started their online trading before Sheldon came on the scene. They could have set up the bank account before he got involved. Also, one of their stocks splits in the middle of the trading day, which is not possible.