Orders & Time-in-Force
The order types and time-in-force options available across spot, perpetual, and outcome markets, from a trader's standpoint.
Order types
| Type | Use it to |
|---|---|
| Market | fill immediately at the best available prices |
| Limit | rest at a price you choose and wait to be filled |
| Trigger (TP/SL) | arm a take-profit or stop-loss that activates when the mark price crosses your trigger, then enters the book |
Limit orders
A limit order executes at your limit price or better, never at a worse price. Whatever does not fill on arrival rests in the book until it is matched or you cancel it.
| Price control | you set the exact price |
| Execution | fills when the market reaches your limit price |
| Fees | maker rate if it rests and is filled later; taker rate if it matches immediately on arrival |
| Best for | precise entries and exits; avoiding slippage |
Example: you want to buy 1 BTC at $50,000 or lower while the market trades at $50,200. Your limit buy rests in the book until BTC trades down to $50,000, or until you cancel it.
Market orders
A market order executes immediately against the best available prices in the book. You trade price certainty for speed: the execution price is not guaranteed.
| Execution | fills immediately against available liquidity |
| Price | takes the best available prices in the book, within a fixed 5% slippage tolerance — see Position & Order Limits |
| Fees | always the taker rate |
| Best for | entering or exiting quickly in liquid markets |
Time-in-force (TIF)
| TIF | Behavior | When to use |
|---|---|---|
| GTC | good-til-canceled — rests on the order book until it is filled or canceled | default resting orders |
| IOC | fills what it can now, cancels the rest | take liquidity without leaving a resting order |
| ALO | post-only — rejected if it would fill immediately | guarantee you're a maker (earn maker rates) |
| GTD | valid until a time you set | time-boxed orders |
An ALO order only ever adds liquidity, so it always pays the maker rate, never the taker rate. That makes it the usual choice for capturing maker rates and for algorithmic strategies. In a fast market an ALO order can be rejected: if the price moves so that the order would cross the spread on arrival, it never enters the book.
What each market supports
Not every option is available on every market:
| Perps | Spot | Outcome | |
|---|---|---|---|
| Market / limit orders | ✓ | ✓ | ✓ |
| GTC · ALO | ✓ | ✓ | ✓ |
| IOC | ✓ | ✓ | market orders only |
| GTD | — | — | ✓ |
| Trigger (TP/SL) | ✓ | — | — |
| Reduce-only | ✓ | — | ✓ |
A GTD order must carry an expiry time, and expiry is measured by the consensus timestamp rather than your local clock.
Perpetual-specific
- Reduce-only — an order that can only shrink your position, never flip or grow it. Use it to close safely without accidentally opening the other side.
- Take-profit / stop-loss — trigger orders evaluated against the mark price (so a wick on last price won't fire them prematurely).
- TWAP — slices a large order into smaller child orders over time to reduce market impact.
Things the engine enforces
- Price–time priority — at a given price, earlier orders fill first.
- Self-trade prevention — if your order would trade against your own resting order, the resting order is cancelled and matching continues; your incoming order is not cancelled by this check.
- Minimum size & price tick — each market has a smallest tradable size and price increment; orders must conform. Check them via
perpMeta/spotMetaon the Info API. - Price limits — orders too far from the mark are rejected to protect the book during abnormal moves.
For the exact request format and how orders are signed, see the Exchange API and Signing.