Atomic baskets

Pick Atomic in the ticket’s Advanced menu, build the basket, set a total and place it. Every leg goes out at once as its own order: a market order, or with TWAP on, a TWAP on the exchange. Nothing keeps running in your browser afterwards, so an atomic order doesn’t need Mirrorlane to stay open.

Each leg is a market with a side, Long or Short, and a share of the total. The shares add up to 100%. Each leg’s size is its share of the total in dollars divided by the market’s mark price, rounded down to the size step. A leg below the market’s minimum size is left out, and the ticket says so: “Some orders are below the minimum size and will not be placed.”

Place atomic order opens a confirmation that lists every leg with its size and share. Then the legs are sent together, up to 15 in one batch. Each leg is a market order that fills no further than Max slippage past the best price, and whatever doesn’t fill within that is cancelled. With TWAP on, each leg is a TWAP over the running time instead.

• Add market finds any market by search, with Long and Short beside each. Press a leg’s side to switch it, and × to remove it.
• Baskets fills the legs for you. Saved holds the baskets you kept. Categories fills them with a category’s perpetuals that can trade now, the most traded in 24 hours first, split evenly, long or short. It leaves out reduce-only markets, markets at their open-interest limit, markets without an insurance fund, markets you trade in isolated margin and markets with no trades in 24 hours.
• Trade as a basket, on the Markets page, does the same for the category you are looking at, with up to 10 perpetuals. It shows what it leaves out and why, and Fill the Atomic ticket opens the trade screen with the legs filled. You set the size and place it from the ticket.
• Save basket keeps the legs on this device, named after them, such as +BTC −ETH.

The order details show Markets (how many legs will be placed), Order value and Fees. The button reads, for example, Place atomic order, $1,000.00.

• Up to 40 markets in one atomic order on Plus or Premium.
• No isolated margin. A market you trade in isolated margin can’t be a leg: “Markets with isolated margin mode are not allowed”.
• Plus or Premium. On a Standard account, trading here is paused. See Account types.
• Atomic shows in the Advanced menu while Advanced order types, in Settings, Trading, is on, as it is by default.

Each leg pays the fee of a market order, or with TWAP on, of a TWAP. The Fees row shows the total for every leg before you place it. See The fee.

• Part of the basket fills. The exchange can refuse a leg, for want of margin for example, while the others fill. The statuses window and the notices say which; finish or close the rest yourself. A leg that breaks a rule the terminal checks first, such as a market that isn’t open, stops the whole basket before anything is sent.
• A leg’s price moves past Max slippage. That leg fills only up to Max slippage past the best price, and the rest of it is cancelled.
• No answer comes back. The legs show as Confirming in Open orders until the exchange reports them. A leg that never appears shows as Not placed and is never sent again.
• You hold the other side. The ticket warns: “You have an active position on the opposite side.” Without Reduce only, that leg shrinks or flips the position.
• The split drifts a little. Sizes come from mark prices, and legs fill at the book’s prices, so the dollar split after filling differs slightly from the shares.

Once sent, Atomic Order Statuses lists each leg as sent and waiting to confirm, or with the reason it wasn’t sent. Fills arrive as notices and in Positions. A market leg has nothing to cancel: it fills at once or ends. With TWAP on, each leg shows in the TWAP table, where you can cancel it.