Hi,

I understand that the broker makes money on the spread that's the gap between the bid and ask. They sell to you about the bid price and attempt to buy it back from the market at the ask price. That is the reason why they are market makers. They create the market for you.

But if a broker is STP so they pass your order directly through to their liquidity supplier, that liquidity supplier like a bank becomes the market maker. Can the STP broker make money since they are not currently performing the buying and selling between you and the market?