If you had the composure to place a bet with that huge some of bitcoin you might have also used a sum close to that and won. That’s gambling, I know this thread is about the highest money lost on a single bet but it will create the wrong signal. In sport betting I know people who stake high and they lose something but they make it up when they win because it is usually big.
My biggest loss in gambling is $1500 in bitcoin and that really hurt so bad, but I tried it again the next day and I made it all up since then I haven’t tried gambling with that sum of money again.