Understanding Guaranteed vs. Non-guaranteed Combination Orders


Provides information about multi-leg orders specifically relating to guaranteed vs non-guaranteed orders.

Multi-Leg Orders

A multi-leg order, also known as combination order, is a special order type comprising two or more components or legs that execute as a single transaction.  Each leg of a multi-leg order is defined with an asset, a leg side, and a ratio relative to other legs.  IB currently supports multi-leg orders with legs that belong to the following asset types: stocks, options, futures, future options and US CFDs.

Guaranteed and Non-Guaranteed Multi-Leg Orders

A guaranteed multi-leg order is an order in which executions are guaranteed to be delivered simultaneously for each leg and in proportion to the leg ratio.  This guarantee is fulfilled by IB or the exchange depending on the way the guaranteed multi-leg order is routed and executed.

Non-guaranteed multi-leg orders are not guaranteed to be executed proportionally to the required leg ratio although every effort is made to execute the order that way. 

Guaranteed multi-leg orders can be SMART routed or directed to a specific exchange, while non-guaranteed multi-leg orders can only be SMART routed. See the table below.

Guaranteed Multi-Leg Order Support by Routing Type

Routing Type



SMART Routed



Exchange Directed



Directed Multi-Leg Orders 

A directed multi-leg order is an order that is routed to a specific exchange that has native support for such an order. Directed multi-leg orders follow the exchange’s rules in terms of allowed number of legs, permitted asset types, and allowed combinations of leg ratios and leg sides. IB never attempts to execute individual legs of a directed multi-leg order separately.

Directed multi-leg orders are guaranteed by the exchange to be executed following the specified leg ratio.  IB does not accept non-guaranteed directed orders.

SMART Guaranteed Multi-Leg Orders

IB supports SMART routed guaranteed multi-leg orders of up to 6 legs. Based on the order marketability, these orders can be routed by the IB system to one of the competing exchanges that support them natively. In addition, 2-legged SMART routed guaranteed US stock/option and US option/option orders can be executed by IB on different exchanges, where each leg is routed separately. Any risk of resulting execution that does not satisfy the required order ratio is taken over by IB.  

SMART Non-Guaranteed Multi-Leg Orders

IB supports SMART routed non-guaranteed multi-leg orders of up to 2 legs. Legs must trade in the same currency and must be stocks, options, futures, or futures options. Supported currencies are: USD, EUR, AUD, CAD, CHF, GBP, HKD, and JPY.

Non-guaranteed multi-leg orders can only be SMART routed.  These orders may be executed natively on an exchange if supported there or executed by IB on one or more exchanges with each leg routed separately. The IB system makes every effort to execute the order according to the specified order ratio, but does not guarantee such an execution. Clients must acknowledge the inherent risk of non-guaranteed multi-leg orders upon order entry.

Non-Guaranteed Combination Orders

A combination order is a special type of order that is constructed of multiple separate positions, or ‘legs’, but executed as a single transaction.  The legs of the combination may be comprised of the same position type (e.g. stock vs. stock, option vs. option or SSF vs. SSF) or different position types (e.g. stock vs. option, SSF vs. option or EFP).  It’s important to note that many combination order types, while submitted via the IB trading platform as a combination, are not native to (i.e., supported by) the exchanges and therefore may not be guaranteed by IB.  Accordingly, IB’s policy is to guarantee only Smart-Routed U.S. stock vs. option and option vs. option combination orders.

As combination orders which are not guaranteed are exposed to the risk of partial execution, both in terms of the quantity of legs and their balance, IB requires account holders to acknowledge the 'Non-Guaranteed' attribute at the point of order entry.  There are two methods for setting this attribute:

  • Method 1 - Users can select the Non-Guaranteed attribute in the Misc. section on the Order Ticket for a particular order
  • Method 2 - Users can add the Non-Guaranteed column to the Order Management section of the TWS



  • Non-Guaranteed combination orders are not available for Financial Advisor allocation orders


The risk of such 'Non-Guaranteed' orders is illustrated through the example below:


Assume the following quotes for a Stock vs. Stock combination order to purchase shares of Microsoft (MSFT) and sell shares of Appl (AAPL).

Current markets

MSFT - 26.30 bid, 26.31 offer
AAPL - 250.25 bid, 250.30 offer

A generic combination is created to buy 1 share AAPL and sell 1 share MSFT, the implied quote would be 223.94 bid, 224 offer.

The following order is entered:
Buy 200 AAPL, Sell 200 MSFT
Pay 224

Based on the current markets, the order would appear to be executable.

  • A buy of 200 shares of AAPL are routed with a 250.30 limit. Only 100 execute.
  • A sell of 200 shares of MSFT are routed with a 26.30 limit. No execution is received as the market moves to 26.29 bid.

With a Non-Guaranteed combination, the 100 shares of AAPL would be placed in the client account, even though no MSFT shares were executed.  The remainder of the combination order will continue to work until executed in its entirety or until it is canceled.

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