Earlier quoted context omitted.
its almost like making bets with money you don't actually have yet is a bad idea
This is literally the definition of fractional reserve banking, used by almost every bank worldwide.
Banking is supposed to be a very boring business (at least under Glass-Steagal-like regulation). Making "bets" with money they don't have isn't something retail banks are supposed to be doing. Yes, we know that some banks were doing this prior to the '08 GFC, but wasn't that supposed to have been reigned in by the reinstatement of Glass-Steagal-like regulation since then? (of course, there is some distinction between retail banks and investment banks, is SVB the former or the latter?)