Remember another thing Gigantor - the repeal of Glass Steagall allowed these banks to use the deposits, savings, and checking of oridinary depositors and customers on the banking side as part of their capital reseves in terms of leverage and capital requirements on these crazy investment vehciels they were gambling on, in the investment side.
I'm telling you, get this book. You will learn more in 700 pages than you ever thought possible on how banking works.