Administering a checking account is not cost-less. Looks like SIVB’s return on assets is 1.87% [1] implying $467 of annual revenue for the account at $25k average balance. This is probably more or less break-even (maybe it’s $200?) - point being is they lose money on small accounts...

[1] https://finance.yahoo.com/quote/SIVB/key-statistics?p=SIVB

It is completely bonkers. But it seems to be working for them, apparently they done quite well last year - got some nice tax cuts too!

https://www.fool.com/investing/2018/04/27/svb-financial-grou...