The problem is three-fold. 1) Too much money in the system from close to 13 years of almost uninterupted qantitative easing. 2) Not enough collateral in the f

The problem is three-fold. 1) Too much money in the system from close to 13 years of almost uninterupted qantitative easing. 2) Not enough collateral in the financial system to offset the liability of holding so much customer money (as a bank), with increased uncertainty about an impending market correction (hence banks favoring short-term, safe returns that they can mobilise very quickly). 3) Not enough collateral to keep leverage in check with mandatory limits (these mandatory limits were suspended through covid-19 times and have just been reinstated, although I may have missed this date being pushed out).