General
Rule 6610 states the core reporting mandate underlying the OTC Reporting Facility and governs FINRA's publication of aggregated market transparency data. Members must report certain over-the-counter transactions to FINRA, and FINRA in turn publishes summary trading data derived from those reports on its public website.
The rule sits at the front of the Rule 6600 Series, which governs the OTC Reporting Facility, or ORF, the FINRA-operated system through which members report last sale information for OTC Equity Security transactions executed away from an exchange. Where Rules 6621 through 6630 govern the mechanics and timing of individual trade reports, Rule 6610 governs something different: the aggregate output FINRA produces from that reported data and makes available to the public.
The rule occupies an unusual position in FINRA's history. An entirely different NASD Rule 6610 existed before 2008 as a stand-alone definitions rule, defining terms such as "Non-Market Maker," "non-exchange-listed security," and "OTC Reporting Facility" itself. That rule has since been superseded by FINRA Rule 6420, which now houses the OTC Equity Security definitions used throughout the Rule 6600 Series. Any reference to "Rule 6610" in materials predating 2008 refers to that defunct rule and has no bearing on the provision addressed here.
The current Rule 6610 was adopted in its present form as part of the 2008 Consolidated FINRA Rulebook initiative. It took effect December 15, 2008, under SR-FINRA-2008-021, per Regulatory Notice 08-57. It has been amended twice since in ways that matter substantively: once in 2010, under SR-FINRA-2010-003, to close a reporting gap tied to the retirement of Nasdaq's PORTAL Market, and again in 2019, under SR-FINRA-2019-019, to expand the scope of published trading data. No further substantive amendment has been confirmed since 2019, though a 2024 FINRA filing made non-substantive technical corrections elsewhere in the Rule 6000 Series without altering Rule 6610 itself.
The Reporting Obligation
Paragraph (a) requires members to report transactions in OTC Equity Securities, other than those executed on or through an exchange, to the OTC Reporting Facility. This includes secondary market transactions in non-exchange-listed Direct Participation Program securities, and it includes Restricted Equity Securities traded under Securities Act Rule 144A. The obligation operates in compliance with both the Rule 6600 Series and the Rule 7300 Series, which governs the ORF's technical participation and processing mechanics.
The exchange exception was added in 2010. Before that amendment, the operative transaction reporting rule contained no explicit carve-out for OTC Equity Security transactions that were reported on or through an exchange, unlike the parallel Alternative Display Facility and Trade Reporting Facility rules, which had always excluded exchange-reported trades from their own reporting obligations. FINRA closed this gap specifically in connection with the 2009 cessation of Nasdaq's PORTAL Market designation function, a change that required conforming amendments across several rules addressing where formerly PORTAL-designated securities would now be reported once that function ended.
This gap-closing amendment illustrates a recurring pattern in FINRA's rulebook maintenance: a structural change in one part of the market, here the retirement of an entire quotation system, can leave residual inconsistencies in adjacent rules that FINRA must separately identify and fix. Candidates and practitioners reviewing older FINRA guidance should treat any pre-2010 description of Rule 6610's reporting obligation as incomplete on this specific point.
Publication of Non-ATS Trading Information
Paragraph (b) requires FINRA to publish the Trading Information for each member with a reporting obligation under Rule 6622(b). Weekly data is published no earlier than four weeks after the relevant week ends. Monthly aggregate volume is published no earlier than one month after the relevant month ends. "Trading Information" for this purpose means two specific data elements: the number of shares of an OTC Equity Security the member executed and reported to FINRA, and the number of separate trades in that security the member executed and reported.
This member-level publication requirement came later than the parallel ATS publication requirement, and understanding that sequencing matters for interpreting the rule's current structure. FINRA had published ATS-level OTC equity volume data, including ATS block-size data, since 2014 under SR-FINRA-2013-042. It did not begin publishing the non-ATS portion of that volume, meaning ordinary member-firm trading executed away from any ATS, until amendments approved under SR-FINRA-2015-020 took effect in April 2016. For roughly two years, FINRA's OTC transparency initiative covered only the ATS side of the market, leaving ordinary internalized and desk-level trading activity outside public view entirely.
FINRA expanded this data again in 2019. The original 2019 proposal, as filed with the SEC, would have eliminated the existing 200-transactions-per-day de minimis exception entirely, publishing every firm's non-ATS volume on a fully attributed basis with no aggregate category at all. The SEC's final approval order confirms FINRA did not adopt that more aggressive approach for the standard publication; the existing de minimis exception under Rule 6610(b)(2)(B) and (C) was retained in its original form.
What FINRA did add in 2019 was a new, separate category: non-ATS block-size trading data. This was designed as a direct complement to the ATS block-size data that already existed since 2014, giving the market comparable visibility into large trades regardless of where they were executed, on an ATS or away from one. Unlike the standard weekly and monthly publication, this new block-size category carries no de minimis exception at all; every qualifying block trade is published on a fully attributed basis regardless of the reporting firm's overall volume.
Rule 6610 aggregates data, rather than disclosing it on a standalone basis, for members averaging fewer than 200 transactions per day across all OTC Equity Securities during the applicable period. It does the same, separately, for members averaging fewer than 200 transactions per day in a specific security during that period. Firms falling under either threshold appear in FINRA's published data only as part of a "De Minimis Firms" category rather than by name.
Trading Information is also aggregated across every Market Participant Identifier a single member uses. This excludes, where applicable, any MPIDs the member uses to report trades executed on its own alternative trading system, since ATS activity is addressed separately under paragraph (c) and would otherwise be double-counted across both publication regimes.
ATS Trading Information
Paragraph (c) requires FINRA to publish aggregate weekly ATS Trading Information for each ATS with a reporting obligation under Rule 6622(b), using the same four-week delay structure applied to non-ATS data. "ATS Trading Information" is defined in near-identical terms to the non-ATS version: the number of shares of an OTC Equity Security executed on the ATS and reported to FINRA, and the number of trades in that security executed on the ATS and reported to FINRA.
There is no de minimis exception anywhere in paragraph (c). Every ATS has its volume published on a fully attributed basis, regardless of size or trading volume. A newly registered ATS handling a handful of trades per week receives exactly the same individualized public disclosure as one of the largest ATSs in the market.
This no-exception treatment predates the 2019 block-size change and served as its direct model. When FINRA later extended block-size transparency to the non-ATS side of the market in 2019, it was applying the same fully-attributed logic already established for ATS data more broadly, rather than creating a novel disclosure concept.
Relevance to Specific FINRA Examinations
This rule has narrow, specific relevance across FINRA's exam programs, and candidates should not assume uniform importance across all of them.
The SIE, Series 7, Series 63, and Series 65 do not test Rule 6610. These exams focus on representative and adviser conduct, suitability, product knowledge, and state securities regulation. A rule governing FINRA's own website publication schedule falls outside all of them, and candidates preparing for these exams can set it aside entirely without exam-readiness risk.
Series 24 candidates should pay attention to Rule 6610 only through the lens of supervisory responsibility. A principal is unlikely to be tested on the specific publication timeframes or the 2019 amendment history. A principal should understand, however, that FINRA's published Trading Information is derived entirely from a firm's own Rule 6622 reports, so any MPID misclassification or reporting error a principal is responsible for supervising has a visible downstream consequence in public data that clients and competitors can see.
Series 57 candidates have the strongest direct relevance of any exam to this rule. Series 57 candidates should know the 200-transactions-per-day threshold precisely, since it determines whether a firm's own trading in a security appears individually in FINRA's published data or is folded into the aggregate "De Minimis Firms" figure. Series 57 candidates should also know that this threshold does not apply to ATS trading or to non-ATS block-size trades, both of which are always published on a fully attributed basis regardless of volume.
Relevance to Working Financial Services Professionals
For compliance officers, market makers, and ATS operators, Rule 6610 creates no independent reporting burden of its own. Published data derives entirely from trades already reported under Rule 6622, meaning there is no separate filing or submission tied to Rule 6610 itself.
It does create real competitive and reputational consequences. A firm's OTC trading footprint, including its market share in specific securities, becomes visible to competitors, institutional clients, and regulators once that firm crosses the 200-transactions-per-day threshold in either direction, security-specific or firm-wide.
For firms operating an ATS, there is no volume-based grace period of any kind. Every ATS, regardless of size, has its trading volume published on a fully attributed basis from the day it begins reporting. This is a planning point smaller or newly launched ATSs should build into their compliance program from the outset, since some newer market entrants mistakenly assume a transparency threshold exists for ATS activity the way one exists for ordinary non-ATS trading.
Compliance personnel reviewing a firm's Rule 3110 supervisory procedures for trade reporting accuracy should treat MPID hygiene and tape-report classification as directly tied to Rule 6610 outcomes, even though the rule itself creates no separate violation category. An error at the reporting stage under Rule 6622, whether a misattributed MPID or an incorrectly classified non-tape report, surfaces publicly through Rule 6610's publication mechanism. This is the practical reason firms increasingly treat trade reporting accuracy as a public transparency issue tied to their market reputation, not merely as an internal technical compliance matter confined to regulatory risk.
