As soon as they realise you are a “Sharp” they are pretty quick to limit your stakes or shut down your account. For them it’s not about getting market prices right, it’s about balancing bets and getting winners off the books to guarantee themselves a profit.Not exactly ethical, but they still look pretty saintly compared to some of the insider banksters in the stock market or the outright scammers in the crypto market.

There's hardly any financial means these days that really do play fair.