It’s important to understand whether your broker is an “A-book”, “B-book” or hybrid broker.
When a trade is passed through to a liquidity provider (LP), this is A booking. This broker simply acts as the intermediary between you and the liquidity provider(s). Brokers make money by marking up the spread or charging a commission.
If the brokers keep their customers’ trades on their own book, that’s B booking. Since something like 90% of retail forex traders lose 90% of their money within 90 days, operating a B book can be extremely profitable. Think about it. If you know someone is putting on a losing trade, might as well take the other side of the trade.
Most brokers operate both an A and B book (aka hybrid model), selecting which trades are placed with an LP vs. internally.
In the bybrid model, the broker will most likely hold the trades of losing traders for themselves and pass the trades of profitable traders through to the market (or at least hedge against these trades).