You’re ignoring survivorship bias. Bad market makers don’t last long, precisely because it’s possible to lose a lot of money. More realistically, a strat witho

You’re ignoring survivorship bias. Bad market makers don’t last long, precisely because it’s possible to lose a lot of money. More realistically, a strat without edge gets eaten alive by costs, or by toxic flow (as other MM are either better at pricing or faster at getting out of the way). But yes a decent HFT MM will have down and out circuit breakers.