> ## Documentation Index
> Fetch the complete documentation index at: https://docs.astaria.trade/llms.txt
> Use this file to discover all available pages before exploring further.

# Order Types and Matching

Astaria supports order types designed for efficient trading of event-linked perpetuals.

## Order Types

* **Market Order**: Executes immediately against available liquidity.
* **Limit Order**: Executes at the selected limit price or better.
* **Stop Market Order**: Becomes a market order once the trigger condition is met.
* **Stop Limit Order**: Becomes a limit order once the trigger condition is met.

## Execution Options

* **Reduce Only**: Can only reduce or close an existing position.
* **Post Only**: Adds liquidity to the order book and will not execute immediately.
* **Immediate or Cancel (IOC)**: Executes immediately for any available size, with the remainder canceled.

## Matching

Astaria uses price-time priority for order matching.

Orders at the best price execute first. If multiple orders share the same price, the earliest order receives priority.

## Resolution-Aware Restrictions

As a market approaches resolution, Astaria may restrict certain actions to reduce settlement risk. Depending on the market state, this can include:

* Reduced maximum leverage
* Restrictions on opening new positions
* Cancellation of resting orders before the final settlement window