Not quite. You pay a bondsman 10%. The bondsman turns around and pays the full bail amount to the court. If you show up, the bondsman gets their money back from the court but keeps your 10% as a fee. If you don't show up to court, the bondsman does not get their money back and is left holding the bag for the other 90% of the bail amount.

What professor has $25M lying around to pay the bond? Yes, Palo Alto homes are expensive, but those are not typically the homes professors are living in.

Their house is valued at $4m on Stanfords campus, fwiw.

What bondsman has $250 million in the bank to do this? Seems like such an obscure niche to be in.

I doubt they used a bondsman. $25 million is a pretty steep fee. They likely paid the entire bail amount and will get that money back once SBF shows up to court.

That is if you have no collateral to back it up

If you skip town, you lose the whole bond.

If you use a bondsman, you lose the 10% no matter what. If you use a bondsman and skip town, you're out 10%, and they're out the other 90%. Hence why bondsmen employ bounty hunters.