Ross Levine, an economist at the University of California, Berkeley business school who specializes in banking and finance, on the SVB collapse
SVB took lots of uninsured deposits from 100 or 200 really large depositors and invested a large portion of that money in long-term securities—very, very safe securities, so US Treasury securities and government-backed mortgage securities. This created an extremely fragile bank with respect to interest rates: Interest rates go up, bond prices go down, and that change is particularly big for long-term securities. So the value of the assets of SVB fell as interest rates rose.
The fact that it had a few large, uninsured depositors who were very well connected meant that any sign of vulnerability triggered a flow of information such that the uninsured depositors wanted to remove their deposits, and everything unraveled very quickly.
They couldn’t stop the bank run once the word about the risk got out. CAO Greg Becker should be held accountable for not keeping his bank safe from the risks his investments made on depositors money.