Because the market maker bets with the customer, the money earned by the customer is the money it loses. Under the unilateral trend, customers are almost always long or short, and traders have to take orders from customers, so it is likely to be a loss, right? -That's right.
If the trader's order is rushed to the market, then the customer's profit is the loss of his counterparty in the market, right? -That's right.
Therefore, since it is a zero-sum market, the number of counterparties cannot be only 1, so big losses generally do not occur!