Reply #16: Among other things, it kept deposit banks seperate from investment banks

[MadHound]

Which in turn limited the amount of market speculation a bank could engage in and and control. It also protected bank depositors from seeing their money disappear, since a bank couldn't engage in wild speculation that would bankrupt it. Without Glass Steagall, banks were free to invest in derivatives, credit default swaps and other risky investments, which they covered with their depositor's money.

This need is as great today as it was in the thirties when it was originally passed.