FAZ can move way more than +75% in a day. It's a 3x etf. That means if the bank stocks drop 30% tomorrow, FAZ goes up 90%! If the banks drop 50%, FAZ goes up 150%!
Plus there is also the compounding effect. If bank stocks drop 20% in one day, FAZ goes up 60%. Then if they drop another 20%, FAZ goes up another 60% from its new price. The net gain would be +156%! Theoretically, FAZ has no upper limit. The only problem - bank stocks have to drop.