Frequently asked questions

What is IEX?

IEX is a stock exchange - a market that matches orders to buy and sell securities. IEX supports displayed and non-displayed trading, and the routing of orders to other trading centers.

Who owns IEX?

IEX is owned by a collection of mutual funds, hedge funds, and venture capital funds including Bain Capital Ventures, Belfer Management, Capital Group, Cleveland Capital Management, Greenlight Capital, IVP, MassMutual Ventures, Maverick Capital, Pershing Square, Sapphire Ventures, Scoggin Capital Management, Senator Investment Group, Spark Capital, TDF Ventures, and Third Point Partners, as well as family offices and IEX employees.

How can I invest in or support IEX?

Unfortunately, IEX is not a publicly-traded company, and we are currently not accepting outside investment.

Who can become a Member of Investors Exchange?

Any registered broker or dealer that is a member of another registered national securities exchange or association, or any person associated with such a registered broker or dealer, is eligible to be, and to remain, a Member of Investors Exchange. Broker-dealers must maintain an active clearing relationship with an NSCC-member clearing firm. For more information about becoming a Member of Investors Exchange, please see Membership.

What is the IEX order book priority?

IEX order book priority is: Price - Display - Time.

What order types does IEX support?

IEX offers six order types for continuous trading: Market, Limit, and four types of Pegs: Midpoint Peg, Discretionary Peg™ (D-Peg®), Primary Peg, and Market Maker Peg. IEX also offers four order types to specifically participate in IEX Auctions: Market-On-Open, Limit-On-Open, Market-On-Close, and Limit-On-Close. For more information, please see IEX Order Types and Exchange Rule 11.190.

Does IEX have any broker-dealer affiliates or owners?

IEX Group, Inc. wholly owns Investors Exchange LLC (the national securities exchange) and IEX Services LLC (the Exchange's affiliated broker-dealer). IEX Services LLC is solely responsible for outbound order routing for the Investors Exchange and the maintenance of the IEX error account.

Does IEX have any proprietary trading or affiliated entities engaged in proprietary trading?


Is IEX a block trading venue?

IEX is not exclusively a block venue, but block trading does take place on IEX.

What are IEX's hours of operation?

8:00 a.m. - 5:00 p.m. Eastern Time. During this time, our operations desks are available to assist you in answering your inquiries and address any trading, technological or other matters.

What fees does IEX charge?

For more details on fees, please see the Exchange Fee Schedule.

Does IEX pay maker-taker rebates?


Does IEX publish market data?

Yes, for more details on IEX market data, please see Market Data and Apps.

Does IEX support non-displayed orders?

Yes, IEX supports non-displayed orders, reserve orders, and minimum quantity functionality for non-displayed orders. Additionally, IEX accepts displayed orders and publishes a displayed quote via TOPS and the SIP.

What is IEX Services' Market Participant Identifier (MPID)?


What is Investors Exchange's Market Identification Code (MIC)?


Does IEX accept directed orders from retail broker platforms?

IEX accepts orders from a number of brokers with different business models, including retail and online brokers. Please see the retail and online brokers listed on Members.

How does IEX calculate the NBBO and protect orders resting on its book from trading based on stale market data?

Trading venues, including Exchanges, ECNs, ATSs/Dark Pools, and their participants, including Brokers, Trading Firms, and Investors, access market data services at varying speeds. When a venue consumes market data at a slower speed than some of its participants, the venue may calculate pricing information at a slower rate than its own market participants. Depending on technological choices offered to and made by a participant, such participant on the venue may have more up-to-date information than the venue itself about the real-time price of a stock.

When a venue is slower than its participants to process changes in stock prices and lets its participant have the fastest possible access to its matching engine (i.e. through colocation), the result can be the venue executing trades at a Stale Price giving the "faster" trading participants' orders an advantage at the expense of orders relying on the venue for accurate pricing.

IEX attempts to guard against this scenario by adopting cutting edge technology solutions:

  1. IEX’s low-latency ticker plant normalizes direct market data feeds from all protected US equity venues.1 This currently allows the IEX Matching Engine to calculate the NBBO, which will then be used to price trades on our exchange, in under 350 microseconds.2
  2. IEX's POP Architecture (patent-pending) introduces a 350 microsecond communication buffer between the IEX Matching Engine and all IEX market participants.3 This architecture is designed to prevent an IEX market participant that is able to calculate the NBBO faster than IEX from executing a trade against another IEX market participant on IEX before our Matching Engine can calculate the price for all market participants at any given moment, but most importantly, following a quote change.4
  3. Additionally, IEX offers to its members an order type that uses a formula designed to protect the user of the order type from trading at sub-optimal prices based on microsecond/millisecond changes in the cross-exchange order-book (i.e. it uses a predictive formula to protect the user from getting run over at the midpoint during a crumbling quote). Read more about Discretionary Peg™ orders.

What away trading centers are accessed by the IEX Router?

The IEX Router routes orders to all away trading centers disseminating a protected quotation pursuant to Rule 600(b) of Regulation NMS under the Act. The current set of destinations are listed in Exchange Rule 2.220(a)(7).

1 IEX uses proprietary market data feeds from all registered U.S. equities exchanges as its primary source of market data. IEX uses the SIPs to read the Consolidated Last Sale, Limit Up-Limit Down Reference and Band Prices, and administrative messages including halts, pauses, resumes and, additionally, as redundancy for the direct proprietary feeds. IEX’s ability to process stock price changes faster that its fastest participants may be hindered in scenarios where it has failed over to the SIP feed.

2 Under normal operating conditions.

3 The IEX POP adds 350 microseconds to order and trade communications including e.g. new orders, order cancellations/modifications and trade execution reports. Members who utilize cancel-on-disconnect functionality should note that a loss of connectivity signal must also travel through the IEX POP before IEX becomes aware of the loss of connectivity.

4 Trading on IEX is subject, without limitation, to the Disclaimer of Warranty provision of the IEX User Agreement and IEX Rule 11.260.