They are secondary, partial value sureties, his parents are full-value sureties.
(The relation between bond amounts, sureties, and security interests in the federal system is often radically different than state systems, for a variety of reasons, not least among them that bail bonds firms aren’t as politically powerful in the federal government as they are in state governments.)
This is not even, "put a $750k lien on a brokerage account (with more than that in it) until the trial is over".
This is, "We will owe you $750k if the defendant flees, which you can then try to collect."
1: "residential ground lease" not "fee simple"
In some cases, Stanford will buy on-campus homes and renovate them, and then resell them.
And people thought the skills he developed running FTX weren't useful...
Maybe the purpose of $250m is to get attention not to mean anything more than $5m (considering if he skips they are not collecting $250m