What is a market maker?

The robot on the other side of every trade, so there's always someone to trade with.

In a small market you can't always find a human who wants the opposite side of your stake at this exact second. So an automated market maker stands in the middle: it always quotes a price, always takes your trade, and adjusts the chance after every one.

It isn't betting against you. It's furniture, the thing that keeps the market open 24/7.