Those high rollers almost had nothing to fear.
I guess, what they are thinking is that, if they lose continuously, they will just bring their money back from a single win, given that the bets that they are betting is high.
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Sometimes there are such long streaks that can ruin any pocket, so if the high roller does not play at super low stakes, then he has something to fear. Plus, the distance itself, sooner or later, takes away all the money, so if you use all the money for the game, sooner or later you will lose all of it.