So, Mr George had $500,00 at SVB, $250,000 is covered by the FDIC.
Where did the other $250,000 come from specifically so as to allow George to withdraw it on Monday US time which they would then go and deposit probably in somewhere else like JP Morgan or BOA etc.
FDIC funds if necessary. The FDIC is now the bank. It created a new trust entity on Friday, and that business entity now owns and runs the bank.
The FDIC collects deposit insurance premiums, so it has quite a lot of money on its own. It’s then backstopped. It’s assuming the assets and the liabilities of SVB and Signature. In both cases the assets almost surely exceed the deposit liabilities, but the assets need to be managed and liquidated across a few years.
So can the FDIC run a bank? Or two? Of course! It does that all the time. It reportedly immediately offered SVB staff 45 day contracts at 150% of salary. It has its own personnel on retainer, including forensic accountants, auditors, security teams, managers, lawyers, etc. Usually it gets a few weeks to spin up, but it can spin up faster if needed (as in these two cases). And it’s REALLY good at this.
SVB’s and Signature’s previous management no longer have control. That control has already passed to the FDIC’s chosen managers. However, previous management personnel have certain legal obligations that may apply, and the new owner has the option to retain them in some capacity (consulting usually).