Post-Only Order

The post-only order is a limit order that ensures the order will be added to the book and not match with a pre-existing order. If your order matches with a pre-existing order, your post-only limit order will be rejected.

The Post-Only Order ensures that you will receive the maker rebate, and not pay a taker fee. It prevents placing a limit buy order that matches against the sell side of the order book (and vice versa, for sell orders), which would normally result in taker fees.