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

# Atomic

> Submit a weighted basket of market orders together for a pair trade or a position across several markets.

An Atomic order submits several market orders across different markets together. You build a basket of **long** legs and **short** legs, give each leg a weight, and enter one **Total size** in USD. Pacifica splits the total across the legs by weight, converts each leg to a token amount at its mark price, and submits every leg together in one batch.

<Frame caption="Atomic form with a BTC long and an ETH short. The form shows each leg's size, leverage and the total margin required.">
  <img src="https://mintcdn.com/pacifica-fi-docs-migrate-92/VCAzZXadRgTcpglq/images/order-types/atomic.png?fit=max&auto=format&n=VCAzZXadRgTcpglq&q=85&s=1f2cfd40931c006279a6bc9ec99e14b4" alt="Atomic order form with long and short leg boxes, per-leg weights, total size, Reduce Only and Execute Atomic Order button" width="360" data-path="images/order-types/atomic.png" />
</Frame>

<Note>
  Atomic does not guarantee an all-or-nothing fill. One leg can fill even if another is rejected or only partially filled.
</Note>

## How it works

1. The market you are viewing is added as the first long leg. Use **Add long** and **Add short** to add more legs, up to 5 on each side, and click a leg's symbol to swap it for another market.
2. Set each leg's **weight**. Weights are relative, so they do not have to add up to 100. The form shows each leg's effective share, USD notional, token amount, leverage and estimated liquidation price.
3. Enter the **Total size** in USD, or use the slider and percentage buttons. 100% sizes the basket to the largest notional your idle margin allows across all legs. **Rebalance** resets every leg to an equal weight.
4. Click **Execute Atomic Order**. Each leg is signed as a market order with your **Max Slippage**, and all legs are sent to the exchange in a single batch request. Each leg can fill or fail independently.

## Settings

| Setting               | What it does                                                            |
| --------------------- | ----------------------------------------------------------------------- |
| **Long / Short legs** | Up to 5 markets per side. A market can appear only once in the basket.  |
| **Weight**            | Each leg's share of the total size, relative to the sum of all weights. |
| **Total size**        | The USD notional of the whole basket.                                   |
| **Reduce Only**       | Every leg is reduce-only, so the basket only closes existing positions. |
| **Max Slippage**      | Applies to every leg individually.                                      |

The **Margin** row shows the total initial margin the basket needs: each leg's notional divided by that market's leverage, summed.

## Example

You want a basket with \$1,000 of total notional, split equally between a BTC long and an ETH short:

* Set the long leg to **BTC** with weight 50, the short leg to **ETH** with weight 50 and **Total size** to \$1,000.
* The form shows \$500 of BTC and \$500 of ETH, with the token amounts calculated from their current mark prices.
* On **Execute Atomic Order**, both market orders are submitted together.

## Good to know

* Each leg is an ordinary market order on its own market. Fills are shown per market in **Trade History**, and the positions appear separately in **Positions**.
* Legs are validated independently by the engine. If one leg is rejected (for example, it is below that market's minimum order size or you lack margin), other legs may still execute. Check **Trade History** and **Positions** after submitting a basket.
* Each leg's slippage protection applies to that leg alone, so a thin market in the basket can be partially filled while the others fill completely.
* Atomic orders are not strategies. They do not appear in the **Strategies** tab.