A Matching Engine that is designed to calculate the True Price™ for a stock uses real-time pricing information consolidated from displayed protected markets in order to prevent its market participants from receiving and acting upon changes in market data before the market itself, on the market's own matching engine. True Price™ determines a trading venue's ability to price trades of a stock which are pegged to or derived from the National Best Bid and Offer (NBBO)2.
Various trading venues, including Exchanges, ECNs, ATSs/Dark Pools, and their participants, including Brokers, Trading Firms, and Investors, access market data1 services at varying speeds (e.g. SIP4 vs. Direct Feeds3). When a venue consumes market data at a slower speed than some of its participants, it is possible for the venue to calculate pricing information at a slower rate than its own market participants.
In other words, 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.
What does this mean in practical terms? 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 is using cutting edge technology:
* IEX uses direct proprietary market data feeds for all of the 11 registered exchanges.
** The IEX POP adds 350 microseconds to order and trade communications including e.g. new orders, order cancellations/modifications and trade execution reports.
Even a venue that takes Direct Feeds3 may be slower than its participants that are using hardware assisted feed handlers, algorithms and other technologies tuned for the absolute minimal latency. A Venue that offers products to speed up market access such as colocation, binary communication protocols, 40Gb Ethernet and microwave communication may further enable its Participants in calculating and responding to changes in the NBBO faster than the Venue's own matching engine, contributing to the occurrence of Stale Price executions.
True Price would be relevant in the following order scenarios:
The NBBO is currently 10.00 x 10.04 with a midpoint price of 10.02
An investor has an order resting on the order book: SELL 10,000 XYZ @ MIDPOINT PEG, which is determined to be 10.02.
The NBBO updates to 10.03 x 10.04 with a new midpoint price of 10.035
A Venue that provides True Price will only allow the Midpoint Peg Sell order to execute at $10.035, the most up-to-date and accurate midpoint price according to the venue.
A Venue that is slower to update the quote change than some of its own participants may allow a fast participant to execute a Buy order against the Midpoint Peg Sell order at the stale midpoint price of $10.02, a price $.01 outside the National Best Bid price and $.015 worse than the new midpoint price.
The NBBO is currently 30.00 x 30.05
The NBBO updates to 29.95 x 30.00
An investor has a non-displayed order resting on the order book to Buy 10,000 XYZ @ 30.04
A Venue that provides True Price strives to decrease the occurrence of Stale Price executions and will not allow the Buy order to execute at a price above $30.00, the most up-to-date National Best Offer price.
A Venue that is slower to update the quote change than some of its own participants may allow a fast participant to execute a Sell order against the resting Buy order at the stale price of $30.04, a price $.04 outside the National Best Offer price as determined by IEX's cutting edge technology.
An academic study produced jointly by Shengwei Ding (Wells Fargo Securities), John Hanna (Redline Trading Systems, a market data technology company), and Terrence Hendershott (University of California, Berkley) was published on January 3, 2014. The study compared the price dislocations between the NBBO calculated by Direct Feeds versus the SIP. The study found, for example, an average of 49,624 price dislocations in Apple (AAPL) over four days in May of 2012 (May 2nd, 10th, 18th, and 25th).
From Wikipedia: In finance, market data is price and trade-related data for a financial instrument reported by a trading venue such as a stock exchange. Market data allows traders and investors to know the latest price and see historical trends for instruments such as equities, fixed-income products, derivatives and currencies.
The market data for a particular instrument would include the identifier of the instrument and where it was traded such as the ticker symbol and exchange code plus the latest bid2 and ask price and the time of the last trade. It may also include other information such as volume traded, bid and offer sizes and static data about the financial instrument that may have come from a variety of sources. There are a number of financial data vendors that specialize in collecting, cleaning, collating and distributing market data and this has become the most common way that traders and investors get access to market data.
From Reg NMS Rule 600
From Wikipedia: Delivery of price data from exchanges to users, such as traders, is highly time-sensitive and specialized technologies, direct proprietary market data feeds, designed to handle collection and throughput of massive data streams are used to distribute the information to traders and investors. The speed that market data is distributed can become critical when trading systems are based on analyzing the data before others are able too, such as in high frequency trading.
From the Exchange Act of 1934 as amended
(22)(A) The term "securities information processor" means any person engaged in the business of (i) collecting, processing, or preparing for distribution or publication, or assisting, participating in, or coordinating the distribution or publication of, information with respect to transactions in or quotations for any security (other than an exempted security) or (ii) distributing or publishing (whether by means of a ticker tape, a communications network, a terminal display device, or otherwise) on a current and continuing basis, information with respect to such transactions or quotations. The term "securities information processor" does not include any bona fide newspaper, news magazine, or business or financial publication of general and regular circulation, any self-regulatory organization, any bank, broker, dealer, building and loan, savings and loan, or homestead association, or cooperative bank, if such bank, broker, dealer, association, or cooperative bank would be deemed to be a securities information processor solely by reason of functions performed by such institutions as part of customary banking, brokerage, dealing, association, or cooperative bank activities, or any common carrier, as defined in section 3 of the Communications Act of 1934, subject to the jurisdiction of the Federal Communications Commission or a State commission, as defined in section 3 of that Act, unless the Commission determines that such carrier is engaged in the business of collecting, processing, or preparing for distribution or publication, information with respect to transactions in or quotations for any security.