Update: original comment should be. 300B/1.2T*(10% of bank funds) = 2.5%. If I'm reading comment correct. Also I believe the whole private credit ecosystem is about 1T.
In a catastrophic scenario: if the whole asset class went to 0 (on the banks asset sheet they would lose 2.5% - absorbable pain assuming its not leveraged through creative financial mechanisms).
I would wager that risk is more concentrated on certain institutions instead of across the board so acute pain likely.
And then that 25% is 10% of US banks' entire lending portfolio, so private credit is about 2.5% of their entire portfolio.
That's only loans to non bank financial institutions.
Total bank balance sheets are about $25T.