> For the complete documentation index, see [llms.txt](https://docs.hello.trade/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hello.trade/about/trading/order-types.md). # Order Types Understanding different order types and how they execute in the market. Every order carries a price bound: each type below has an explicit worst-case price that is signed and margined exactly. There are no unpriced order types (market) — for immediate execution, use a crossing Limit IOC with your slippage tolerance as the limit price. ## Order Type Execution Behavior * **Limit** — Executes at your specified price or better. * To trade immediately (market-style execution), place a **crossing Limit IOC**: set the limit price at your maximum acceptable slippage (e.g. buy with limit = mark × 1.01 for a 1% bound). It fills immediately up to your bound and cancels any remainder — speed of a market order, with a guaranteed worst-case price. * Supports an optional `reduceOnly` flag (see below). * **Stop-Limit** — Becomes a limit order when the market reaches your stop (trigger) price. Requires both `stopPrice` and `limitPrice`. * **Stop-Loss** — Closes (part of) your position when the market moves against you. Places as a Stop-Limit: requires a `stopPrice` (trigger) **and** a `limitPrice` (worst acceptable execution price). * **Take-Profit** — Closes (part of) your position at a profit target: becomes a limit order when the market touches your trigger price. Requires a `stopPrice` (trigger) **and** a `limitPrice` (worst acceptable execution price). ### Reduce-Only Orders `reduceOnly: true` marks an order that may only ever **reduce** your position — it can never open one, flip it, or grow it. Supported on **Limit, Stop-Limit, Stop-Loss and Take-Profit**, resting or immediate. Requirements: * You must hold an open position in that instrument. * The order must be on the opposite side to the position. * Quantity must not exceed the position size. * Where several reduce-only orders would be reached by the same price move, their combined quantity must not exceed the position either. A stop-loss below the market and a take-profit above it are not combined — no single move reaches both — so you may hold both at full size. A reduce-only order may rest on the book. It is kept in line with your position as that position changes, and cancelled once the position is closed or flipped. ### Post-Only Orders `instructions: ["PostOnly"]` marks an order that only adds liquidity. If it would match immediately, it is cancelled. Supported on **Limit** and **Stop-Limit** with `GTC`, `GTD` or `DAY`. **Stop-Loss & Take-Profit Modes:** SL/TP orders support two modes controlled by the `closePosition` parameter: **Managed Orders** (`closePosition: true`): * Quantity automatically syncs with position size as it changes * Only one managed SL and one managed TP allowed per instrument * One-Cancels-Other (OCO): when managed SL or TP fills, the other is automatically cancelled * Automatically cancelled if position closes or direction flips * Cannot specify quantity - server manages it based on current position * Requires either an open position, or a resting entry order on the same instrument to attach to. It can only reduce a position — it can never open one. **Unmanaged Orders** (`closePosition: false`): * Fixed quantity specified by you (like regular orders) * Multiple unmanaged SL/TP orders allowed per instrument * **Requires an open position.** Place the position first, then attach the trigger. * Reduce-only: it can only close part or all of your position — it can never open or flip one. * The quantity you set is an upper bound: the order is kept in line with your position as it changes, and cancelled once the position closes or flips. ### Attaching SL/TP to an entry order There is no native bracket / OTOCO order type, and no OCO between an entry order and its SL/TP — OCO exists only between a managed SL and a managed TP. What you can do: * **Managed** SL/TP may be placed while an entry order is still resting. They stay inert until the entry fills, then size themselves to the resulting position. * **Unmanaged** SL/TP require the position to exist first, so place them after the entry fills. Neither can open a position on its own, so an entry that never fills cannot leave you with a trigger that opens one. If you cancel the entry order, cancel any managed SL/TP you attached to it. *** ## Time in Force Controls how long an order remains active: * **GTC (Good-Til-Canceled)** - Remains active until filled or manually canceled * **IOC (Immediate-or-Cancel)** - Fill immediately, cancel any unfilled portion * **FOK (Fill-or-Kill)** - Fill entire order immediately or cancel entirely * **GTD (Good-Til-Date)** - Expires at specified `expiryDate` timestamp * **DAY** - Expires at end of trading day 00:00:00 UTC *** ## Order Type Compatibility Matrix
TypeGTCGTDFOKIOCDAY
Limit✔️✔️✔️✔️✔️
StopLimit✔️✔️✔️✔️✔️
StopLoss❌❌✔️✔️❌
TakeProfit❌❌✔️✔️❌
*** ## Required Price Fields | Type | `limitPrice` | `stopPrice` | | ---------- | ------------ | ----------- | | Limit | required | — | | StopLimit | required | required | | StopLoss | required | required | | TakeProfit | required | required |