Maker fee

The fee charged when an order adds liquidity to the order book instead of matching an existing one. It is normally lower than the taker fee, and on some venues makers are rebated rather than charged.

Definition

A maker fee applies to an order that rests on the book waiting to be filled. By sitting there, the order gives other traders something to trade against, and the exchange prices that contribution differently from the act of consuming it.

Why exchanges split the two rates

An order book only works if orders are resting in it. Charging makers less, or paying them, is how a venue buys the depth that makes it usable. The taker fee then funds that arrangement.

The gap between the two rates is therefore not a discount for good behaviour, it is the mechanism that keeps the book populated. On venues with rebates rather than fees for makers, the incentive is explicit.

How you end up on the maker side

By placing a limit order at a price that does not immediately match. If your limit crosses the spread, it fills instantly against a resting order and you are a taker, whatever the ticket said when you placed it.

A post-only order removes the ambiguity: it is cancelled rather than filled if it would take liquidity, so it can never be charged the taker rate.

What it is worth

Enough to matter for anyone trading often, and close to irrelevant for someone opening a position and holding it for weeks. The fee difference is a per-trade cost, so it compounds with turnover, not with time.

Rates are set per venue and per fee tier, frequently tied to volume or to staking a protocol token, and they are revised regularly. Read them on the exchange rather than carrying an assumption across from another one.

Where you will run into it

In the fee schedule of any order-book perpetual DEX, in the estimated cost shown on an order ticket, and as the target of post-only and market-making strategies.