Another 10% was low % 5yrs bonds which they had to sell early with penalties to cover the run on the bank which incurred considerable losses. I would think a VC bank knows that some of its VC investments would not outperform. My understanding is that if the run does not happen, it's business as usual, nothing like '08 when borrowers started failing to pay en mass on internationally overrated loans in AAApackages.

Bank regulations are designed to ensure that this type of thing is a shareholder (and pref/AT1) risk - I haven't seen any claims that they were inappropriately or incorrectly rating those risks for capital purposes (but perhaps they were, who knows).

They also hold (held?) $80bn in mortgage backed securities, which I'm consistently suspicious of how much is really grade A investment material.