Risk management has far more depth and consequences than you realise. For example, by far the safest form of investment would be 10yr T-bills held to maturity. Which is what SVB had. The Fed made their paper value worthless because of the high interest rate they set. If they were greedy and opted for highest yield then there would have been a good chance that they stuck around longer.

Problem is that I'm not sure wether to blame the fed or the banks.