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

# Advanced Order Options: Post Only, Reduce Only, Hidden, Iceberg and OCO

> Use Post only, Reduce only, Hidden, Iceberg and OCO orders on Everstrike to control how an order meets the book and your position.

Open **Advanced** in the order form to change how an order behaves. Each option is independent, and several can be combined.

| Option | What it does |
| - | - |
| **Post only** | Cancels the order instead of taking liquidity. It's only accepted if it rests in the book. |
| **Reduce only** | Never increases your position. The order can only make it smaller or close it. |
| **Hidden** | The order isn't shown in the order book. |
| **Iceberg** | Shows only part of the size at a time: the **visible per slice** amount you set. |
| **OCO** | Pairs the order with a second one: one cancels the other. |

## Post only

A post-only limit order always rests in the book as a maker order. If it would fill immediately against an existing order, it's cancelled instead.

Use it to make sure you never cross the spread by mistake, for example with a mistyped price.

## Reduce only

A reduce-only order can shrink or close a position, but it can't open one, increase one, or flip a long into a short.

Use it on any order meant as an exit, such as a limit take-profit. If you close the position some other way first, the reduce-only order has nothing to reduce and can't open a new position.

> [!NOTE]
>
> Stop losses and take profits use reduce only automatically. See [Stop Loss and Take Profit](https://docs.everstrike.io/trading/stop-loss-and-take-profit.md).

## Hidden

A hidden order works like a normal order but doesn't appear in the order book other traders see.

## Iceberg

An iceberg order shows only a slice of its full size in the book. When a slice fills, the next one appears, until the whole order is done. Set the size of each slice in **Visible per slice**.

Use it to work a large order without showing its full size.

## OCO (one cancels the other)

OCO links two orders. Give both orders the same **OCO group**: if one fills, the other is cancelled.

The classic use is a take-profit above the price and a stop below it on the same position: whichever is reached first fills, and the other one is cancelled.

## Where to see them

Every order's options are listed in its details on the [Order History](https://docs.everstrike.io/trading/order-history.md) page, and trigger orders on the [Triggers](https://docs.everstrike.io/trading/triggers.md) page.


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