The Dodd-Frank bill, passed in the depths of Great Depression 2.0, essentially promises US taxpayer support for big US bank, should they screw up and go broke. It makes a list of "systemically important" banks, adds unwilling banks to the list now and then. These favored banks are required to file a ton of paperwork, including a financial last will and testament, supposedly to guide the Feds in a bailout, should they go over the cliff.
Bad idea all around. The bank managers are encouraged to make stupid loans, because they know the feds will bail them out should the stupid loans go bad. The rest of the world is reassured that US banks will live up to their commitments,no matter how stupid, using money from us long suffering taxpayers.
Better idea. Use the ancient Sherman Anti Trust act to break up any bank so big as to pose a threat to the financial system should it go broke. The justice department still has an entire office full of anti-trust lawyers, who haven't done squat in the last 20 years, other than draw their pay. They ought to be out earning their pay by breaking up banks "too big to fail".