How to Use Limit and Post-Only Orders on dYdX

A post-only order on dYdX isn’t a limit order with a preference attached, if it would match immediately against existing liquidity, it gets rejected outright rather than filled as a regular taker trade.

This guide is part of TradeOnDEX’s dYdX how-to series within Perpetual Futures, and goes deeper on maker-side order mechanics than the general order-types guide covers.

Disclosure: TradeOnDEX may earn a commission from links to dYdX on this page, at no extra cost to you. Full details at the end of this article.

What post-only actually guarantees

A post-only order is either placed onto the order book or cancelled outright, specifically, if any part of the order would match against an existing resting order, it’s rejected rather than executed. This is what guarantees you’ll pay the maker fee (or earn the maker rebate) rather than the taker fee: the order type structurally prevents you from ever crossing the book and executing as a taker.

This means for you, concretely: a post-only order isn’t guaranteed to be placed at all, if your specified price would cross the current book at the moment you submit it, the entire order is cancelled, not partially filled or adjusted to a non-crossing price automatically.

The maker rebate you’re actually earning

Maker fees on dYdX are structured as a rebate rather than a cost, currently around -1.1 basis points, meaning liquidity-providing orders are paid to rest on the book, with the exact rebate scaling somewhat by a trader’s nominal volume and volume share (reported ranges of roughly 0.5 to 1.1 basis points depending on those factors). This means for you, concretely: using post-only orders deliberately, when your strategy allows it, converts what would otherwise be a taker cost into a rebate, a meaningful difference for a strategy that trades frequently.

How to place a post-only limit order, step by step

1. Set your order as a standard limit order first, specifying your price.
2. Enable the Post-Only option before submitting.
3. Submit, if your price would cross the existing book, the order is rejected entirely rather than filled; if it wouldn’t cross, it’s placed on the book as a resting maker order.
4. Monitor whether your order actually rests on the book or gets rejected, and adjust your price if needed for a resubmission.

Risk: what post-only trades away for the rebate

A rejected post-only order means no position at all, not a worse-priced fill. Unlike a regular limit order that might simply rest unfilled, a post-only order that would cross the book is cancelled outright, if you need guaranteed execution, post-only isn’t the right tool, since it can result in literally no order being placed.

Post-only makes the most sense for patient, maker-focused strategies, not urgent entries. If you need to enter or exit a position immediately regardless of fee tier, a standard market or regular limit order is more appropriate, post-only is specifically for traders willing to wait for a resting order to be matched by someone else’s taker order.

The maker rebate amount can vary by your own trading volume and share, not a single flat number. Don’t assume a fixed rebate figure applies to your account. Check your current tier’s actual rate rather than relying on a generically cited range.

Fast-moving markets can make post-only orders rejected repeatedly. In a rapidly moving market, your specified price may cross the book by the time your order is actually processed, leading to repeated rejections if you’re trying to place a post-only order too close to the current price, expect this friction specifically during volatile conditions.

Limit vs. post-only, at a glance

See it for yourself

If your trading strategy can tolerate patience, try placing a post-only order slightly away from the current price and watch how it behaves versus a standard limit order at the same level, to get a feel for the rejection behavior before relying on it for a strategy that matters. You can review current maker/taker rates at dydx.trade.

Frequently asked questions

What happens if my post-only order would cross the current order book?

It’s rejected entirely, not filled as a taker trade and not partially executed, unlike a standard limit order in the same situation.

Does a post-only order guarantee I’ll pay the maker fee?

Yes, if it’s placed at all, since it can only be placed as a resting order, it structurally can’t result in a taker fee; the trade-off is that it might not be placed at all if your price crosses the book.

Is the maker rebate the same for every trader?

No, it scales somewhat with your own nominal trading volume and volume share, so check your specific current rate rather than assuming a single flat figure.

When should I use post-only instead of a standard limit order?

When you specifically want to guarantee maker-side execution (and the associated fee/rebate) and can tolerate the possibility of your order being rejected outright if it would otherwise cross the book.

Affiliate disclosure

TradeOnDEX may earn a commission if you sign up or trade through a link on this page, at no extra cost to you. dYdX’s own affiliate/referral terms are still being confirmed for this site, so links here are direct and untracked for now. This article is educational and is not financial advice. See our disclaimer for the full risk warning.