This is why you shouldn't make large MARKET orders

Stablecoins are quite stable, right? With minimal volatility, correct?

Well, not necessarily on a shallow market, as can be seen on this extreme example of slippage.

If the market order is too large, not even arbitrage bots can save the day for the one who set the market order. This was definitely easy money for counterpart with limit order at 6 EUR/BUSD.

(Possibly this was also during the time when the exchange was unavailable...)