Place OCO Order

Place a one-cancels-other (OCO) order composed of two simultaneous orders. If one executes, the other is automatically cancelled. Send to POST /v1/accounts/{account_id}/orders with class=oco.

Validations:

• type must be different for both legs.
• If both orders are equities, the symbol must be the same.
• If both orders are options, the option_symbol must be the same.
• If sending duration per leg, both orders must have the same duration.

Which fields are required per order type

Each leg’s type[index] follows the same rule (note that market is not a valid type for either OCO leg — see below for why):

Example: bracket-style take-profit / stop-loss

A common use of OCO orders is a bracket exit on an existing position: place a limit order to take profit if the price rises to a target, and a stop order to cut losses if the price falls to a threshold — whichever happens first automatically cancels the other.

For example, holding 10 shares of AAPL bought at $140, you could send an OCO order with:

• Leg 0: type[0]=limit, side[0]=sell, price[0]=150 — sell if AAPL rises to $150 (take profit).
• Leg 1: type[1]=stop, side[1]=sell, stop[1]=130 — sell if AAPL falls to $130 (stop loss).

Whichever leg fills first, the other is automatically canceled.

Why market orders are excluded from OCO legs

A market order executes immediately and unconditionally at the best available price — it doesn’t wait for a trigger condition. Allowing a market type on an OCO leg would defeat the purpose of “one cancels other” conditional logic, since a market order would fill right away rather than waiting to see whether the opposing leg’s condition is met first. For this reason, only limit, stop, and stop_limit are valid types for OCO legs.