On March 6, 2024, by unanimous vote, the Securities and Exchange Commission (SEC) adopted changes to Rule 605 under Regulation NMS, the provision that previously required only entities defined as “market centers” to publish detailed statistics on the quality of execution of “covered orders” in NMS stocks. Amended Rule 605 expands the reporting requirement in many ways:

• by reporting party, to (a) broker-dealers with over 100,000 customer accounts (not just “market centers”); (b) Single Dealer Platforms; and (c) Automated Trading Systems (as a stand-alone reporter, separate from any reports by the broker-dealer operator the ATS);
• by expanding the scope of "covered orders" to include: (a) non-marketable limit orders received outside market hours and executed during market hours; (b) stop orders; and (c) short sale orders not marked short exempt and not subject to price test restrictions under Reg SHO.
• by revising time and size categories to include odd-lot and fractional share orders and measure execution time in microseconds and milliseconds. Timestamps must also contain millisecond granularity.
• by expanding execution quality metrics. This expansion is wide-ranging and, among other things, (a) adds effective over quoted spread ("E/Q") as a reporting metric; (b) requires reporting of average realized spread at multiple periods from 50 milliseconds to five minutes after execution; (c) measures price improvement not only relative to the NBBO, but also relative to the “best available displayed price,” a new baseline that includes available odd-lot liquidity; (d) adds measures of size improvement; and (e) includes fill rate information for non-marketable limit orders.

In the past, Rule 605 reports were practically unreadable for retail investors. They were data-heavy rather than in “plain English” and were reported at the security level, requiring significant data analysis to draw meaningful conclusions. The revised Rule seeks to remedy this deficiency, requiring covered broker-dealers and market centers to provide a Summary Report broken out by S&P 500 and non-S&P 500 securities, by order type (market and marketable limit) and order size, with columns for: average order size (shares and notional), average midpoint, percentage of orders executed at the quote or better, percentage receiving price improvement (both absolute and as a percentage of midpoint); average effective spread; average quoted spread; average effective over quoted spread (or “E/Q” percentage); average realized spread 15 seconds and one minute after execution; and average execution speed, in milliseconds.

While the rule revisions are comprehensive and will require significant programming (or vendor) expense, particularly for broker-dealers newly subject to the rule, many of the changes are welcome. Rule 605 had previously been subject to many increasingly outdated metrics, and firms that route orders will welcome more comprehensive and granular data elements. It remains to be seen whether retail and institutional customers will use the data to demand better execution quality from their broker-dealers or manage order-entry decisions based on the data.

What is meaningful, however, is the timing of this rule revision. These revisions were proposed in December 2022 as part of a package of significant market structure changes, including a proposed Order Competition Rule, a proposed far-reaching SEC best execution requirement known as Regulation Best Execution, and proposals to revise the pricing increments for quoting and trading equity securities and the minimum fees to access that liquidity. These other proposals were very controversial and subject to strong pushback from many parts of the securities industry. Many argued that the SEC should first adopt the proposed amendments to Rule 605 and then use the data from revised Rule 605 reporting to evaluate the other rule proposals. This approach would, of course, delay consideration of the other rule proposals while data were generated under revised Rule 605. The SEC's adoption of just the Rule 605 revisions does not preclude further consideration of the other rules, but it is a welcome development and a step in the right direction.

The Rule 605 amendments will become effective 60 days after the release is published in the Federal Register. The compliance date is currently set for 18 months after that effective date.