they are guaranteed by the FDIC up to 250K, and mercury has set up their systems to spread deposits across multiple banks, to increase the amount guaranteed. s

they are guaranteed by the FDIC up to 250K, and mercury has set up their systems to spread deposits across multiple banks, to increase the amount guaranteed. so, if mercury has a 1M FDIC guaranteed, then you can move 1M per day through their systems with 100% guarantee, but the risk that a bank fails on one particular day is very small, so maybe you can move 10M a day through them, with effectively no risk. 10M a day is 3.5B a year. very few companies are doing transactions on that level, so mercury scales up very well.