From what I understand, the assets were allowed to be on the books at face value, under the assumption they would be held to maturity, but they're worth significantly less on the open market.

I thought the follwoing was an interesting analysis: Aside from the fact that those assets don't seem to be valued at the current price (i.e. are marked at cost basis, not market,) much of it is already pledged as collateral.

https://twitter.com/FedGuy12/status/1634031134505066496

obviously nobody believed those numbers. i had 50% of my 401K in a AAA bond index fund and it lost 15% in 6 months. SVBs assets aren't even close to AAA. They are loaning money to startups, creating deposits out of those loans, and then using those deposits as collateral to issue 10X more loans. That is all perfectly cool and legal, but when all of those startups run out of runway at the same time the party stops.