Order Execution Quality Practice: Read Rule 605 Reports Without Overinterpreting Them

A simulator can make every order look immediate. A live U.S. stock order may fill at a different price, fill partly or not fill at all. SEC Rule 605 reports let you examine aggregate execution statistics for defined groups of orders, not replay your own order or predict your next fill.

This order execution quality practice guide shows how to locate a monthly report, read three common measures and write down what the numbers leave out. It concerns reportable orders in U.S. NMS stocks, not forex, crypto, futures or every possible stock order. It is educational, not personalized trading or broker-selection advice. Live trading can involve loss of capital; reading reports cannot guarantee a better fill.

Quick answer: what does Rule 605 report?

Specified market centers and certain brokers and dealers publish monthly statistics about the execution of covered orders in NMS stocks. Amendments applicable from August 1, 2026 require detailed reports and a monthly summary report. FINRA said the first amended reports, for August 2026, were due before the end of September 2026. These are reporting requirements, not proof that any particular file has been checked or that every firm reports the same order population. See the SEC staff's Rule 605 FAQ and FINRA's June 2026 notice.

Start at a reporting entity's Rule 605 download site or the links maintained by its Designated Participant. An entity can report under different identifiers for different functions. The NYSE Rule 605 directory, for example, lists August 2026 summary CSV/PDF and detailed-report links. That is a directory example, not a claim about figures inside those files or about other reporting entities. Open a specific report before quoting its data. If the summary is easier to read, begin there; a detailed file has more granular security, order-type and size records. Check the month, reporting entity and function, category, units and explanatory notes before comparing anything.

Rule 605 is about execution quality statistics. It is not a route-by-route record of your order, and it is separate from checking a trading platform's registration and identity.

Three measures to read in context

Effective spread: distance from the quote midpoint

The national best bid and offer (NBBO) provides a bid and offer reference. Their midpoint is halfway between the two prices. For an executed buy, the illustrative effective spread is twice the difference between its execution price and that midpoint, using the relevant reference quote. It is not a commission or an all-in trading cost. In a Rule 605 group, the reported average effective spread is weighted by shares executed, including executed portions of partly filled covered orders—not by simply averaging one number per order. See SEC FAQ Q37.

Entirely hypothetical single-execution example: At the relevant order-receipt reference time, a stock is quoted at $10.00 bid / $10.04 offer. The midpoint is $10.02. If a buy order executes at $10.03, its illustrative effective spread is 2 × ($10.03 − $10.02) = $0.02 per share. This is not a figure from a real Rule 605 report. The sell-side calculation reverses the price relationship.

Price improvement: check both reference and unit

In the same hypothetical buy, $10.03 is $0.01 per share better than the $10.04 offer at the reference time. This quote-side illustration is not the monthly summary's percentage price-improvement statistic. The SEC staff explains in FAQ Q38 that the summary percentage uses cumulative improvement less amounts executed outside the quote, divided by the sum of execution midpoint × executed shares. Check whether a column uses a per-share amount or a percentage and which reference price applies before reading it as “better.”

Do not assume every price-improvement field starts on the same date. SEC FAQ Q39 gives a November 1, 2026 compliance date for collecting statistics relative to the best available displayed price; earlier voluntary reporting is possible. Do not demand that field of an August report.

Execution time: whose clock and which orders?

Reported execution-time measures use defined order-receipt or executability and execution timestamps, not the instant you touch a phone screen. A faster average for a category cannot tell you how quickly your next order will fill. A non-marketable limit order that remains unexecuted contributes no hypothetical execution time to an average for executed shares. Check the report's execution, cancellation and nonexecution context as well as the category: marketable and non-marketable orders ask different questions.

A five-step report-reading worksheet

You can do this on paper without placing a trade. If you cannot open the actual file, mark it “directory only; figures not checked” and use the hypothetical exercise below instead.

1. Identify the source: Record the reporting entity, its function or reporter identifier, the month and whether you opened a summary or detailed report.
2. Match the category: Note the security, order type and size grouping where provided. Do not compare different buckets as if they described the same orders.
3. Check the denominator: Record the applicable received, executed, canceled or unexecuted counts or shares as labeled in that file. An executed-share average does not summarize the experience of every submitted order. If a field is absent, write “not shown,” not zero.
4. Write the metric and unit: Copy the *label and unit* for effective spread, the particular price-improvement measure and the execution-time measure. Note the report's reference quote and any definitions or notes.
5. State a limitation: “This is a monthly statistic for defined covered orders; it does not establish the route, price or speed of my next individual order.” If the populations or definitions differ, don't declare a winner from the averages.

For effective spread practice, return to the invented $10.00/$10.04 quote. Change only the hypothetical buy execution price from $10.03 to $10.04. The midpoint remains $10.02: illustrative effective spread rises from $0.02 to $0.04 per share, while quote-side improvement falls from $0.01 to $0.00 per share. These are arithmetic examples, not actual report rows or predictions.

What a favorable number cannot establish

Averages can reflect different securities, sizes, order instructions, liquidity, partial executions and orders that never execute. Even figures for the same calendar month require comparable reporting functions, populations and definitions. The NYSE directory itself warns that cross-market-center figures may not be directly comparable because of market structure and calculation differences. A narrow effective spread does not include every cost, and price improvement does not mean a trade was profitable.

The Trading Simulator is a forex candlestick decision game, not a U.S. stock routing engine or Rule 605 simulator. A useful carryover is the habit of pausing to note assumptions; its virtual outcomes do not demonstrate how live orders would execute. Risk-Reward Practice and Position Sizing Practice address other learning questions, not execution reporting.

Quick questions

Can these reports tell me which broker will give me the best fill?

No. They describe historical, defined order groups, not your next order. A one-number ranking leaves out categories, nonfills, fees and other context. This guide recommends no broker or venue.

Does price improvement mean I made a profit?

No. It compares execution prices with a specified reference price. The asset's subsequent movement and other costs are separate.

Are all orders and assets included?

No. Rule 605 has covered-order conditions and exclusions; it does not apply to every stock order or to forex, crypto or futures trades. For an actual account question, examine your firm's disclosures and order confirmations rather than treating a monthly average as your own fill record.

Keep the conclusion modest

A useful reading session can end without a winner. Write down the entity, month, order group, metric definition and missing context. That is a stronger habit than treating a single number as a promise. Browse more exercises in Articles.

Primary references: SEC Division of Trading and Markets, Rule 605 staff FAQ; FINRA Information Notice, June 17, 2026; NYSE Rule 605 directory (no underlying files used for numerical claims).

Categorised in: Trading Basics