SVB had plenty of assets at "par" value or held to maturity value. But it was insolvent if you marked those to market.
So FDIC is letting First-Citizens buy the assets at closer to their true market value. 20% loss.
That's my understanding but it is kind of a distressing conclusion. SVB had no enterprise value, and the outcome we're getting is financially the same for FDIC as if they just firesold the assets and did a pure winddown?