> "The chief investment office — which invests excess deposits for the bank and was created to hedge interest rate risk — brought in more than $4 billion in profits in the last three years, accounting for roughly 10 percent of the bank’s profit during that period."

The risk office was speculating, not hedging. If they are paid bonuses on profits then they are encouraged to speculate. That office should be bonused on having opposite P&L to the groups they are hedging.