I run a kind of similar service to Yotta (though we haven't launched to consumers yet, and don't have the gimmick of investing some portion of your interest int

I run a kind of similar service to Yotta (though we haven't launched to consumers yet, and don't have the gimmick of investing some portion of your interest into a lotto-style system). Coffeezilla (linked in another comment) did a good job explaining it. Yotta isn't a bank and doesn't hold user funds -- those funds are at a bank (almost definitely, unless they're breaking the law which I have no reason to suspect), and the bank pays FDIC insurance on each of them. This means the funds are safe against a variety of threats, but not all. Being at a bank is also not the same thing as being available (though banks do have availability reporting and capability requirements). From what I recall Yotta contracts with Synapse for integrating into a bank, and the issue is between Synapse and the bank they work with. Depending on who maintains the authoritative copy of the ledger (the bank or Synapse), the bank may only know the total amount in all combined user accounts and periodically audits of individual accounts -- so they could have ended up in a situation where $X in the bank for Y users, but the total on the Synapse's ledger for that same set of Y users exceeds $X, something which is never supposed to happen unless you're a (highly regulated) bank. If that happened there would probably need to be a much more detailed and time consuming audit of every transaction to determine the "real" balance of each account, and figure out why it doesn't match the total the bank has. Depending on how Synapse implemented their ledger (and this is continuing to assume they are the system of record), that may involve restoring backs and trying to piece together everything from data that was not necessarily intended for this purpose. Because, in this scenario, the bank doesn't know who owns which dollars it has in Synapse's account it can't give those dollars back to their depositors. If worse comes to worse, the bank will sort it out by asking depositors for proof of deposits and then try to correlate those to Synapse's best guess at data that matches total deposits. If Synapse did something with user funds (not the data on their ledger, the actual dollars) other than what the user directed, then there could be big trouble for them and I'm not sure if the FDIC coverage helps there, or if it will be a civil process to try to make everyone whole, or something else entirely. Based purely on the reporting I've overheard and no direct insight (or even researching it beyond the reddit post and this thread), that's my best guess as to what is happening.