FINRA Rule 11891

The Core Definition: "Obvious Error" in Price, Quantity, or Security Identification

FINRA Rule 11891's operative definition — an obvious error in any term, such as price, number of shares, or other unit of trading, or identification of the security — establishes three illustrative categories of error, connected by such as (a non-exhaustive, illustrative formulation this dictionary has encountered repeatedly, including in FINRA Rule 11220's any other information deemed necessary formulation).

The first category — price — represents the most commonly understood form of clearly erroneous transaction: an execution at a price wildly divergent from the prevailing market (for example, a trade executed at a price an order of magnitude away from where the security was actually trading). The second category — number of shares, or other unit of trading — connects directly to the units-of-trading concepts this dictionary examined throughout FINRA Rules 11361, 11362, and 11840: an order entered for a quantity wildly different from what was intended (a "fat finger" error adding extra zeros, for example) would represent an obvious error in this category. The third category — identification of the security — connects to FINRA Rule 11220's description-of-securities framework and FINRA Rule 11100(d)'s CUSIP requirement: an order entered against the wrong security entirely (perhaps due to a CUSIP or ticker-symbol mix-up) would represent an obvious error in this category.

The obvious error standard itself is significant — it is not merely an error, but an obvious one. This threshold connects directly to Supplementary Material .02's observation that a simple assertion by a member that it made a mistake... may not be sufficient — the error must be evident from the transaction's own terms relative to the prevailing market or other objective reference points, not merely asserted after the fact by the party seeking relief.

Supplementary Material .01: Refusal to Abide by Rulings — A Second FINRA Rule 2010 Cross-Reference

Supplementary Material .01 establishes — it shall be considered conduct inconsistent with just and equitable principles of trade for any member to refuse to take any action that is necessary to effectuate a final decision of a FINRA officer or the UPC Committee under this Rule 11890 Series.

This provision directly parallels the cross-referencing technique this dictionary examined in connection with FINRA Rule 11721's second sentence — failure to abide by [the ascertain-notify-correct] requirement may result in a violation of Rule 2010. Here, the parallel is even more direct: Supplementary Material .01 does not merely state that non-compliance may result in a Rule 2010 violation, but directly characterizes the refusal itself as conduct inconsistent with just and equitable principles of trade — the operative language of FINRA Rule 2010 itself. This confirms, for the second time in this dictionary's coverage of the 11000 series, that FINRA's foundational commercial-honor standard operates as a backstop enforcement mechanism for Uniform Practice Code determinations — here, ensuring that a member cannot simply ignore a final clearly-erroneous-transaction ruling (whether from a FINRA officer in the first instance under FINRA Rule 11892 or FINRA Rule 11893, or from the UPC Committee on review under FINRA Rule 11894) without exposing itself to a FINRA Rule 2010 violation.

The dual decision-maker reference — a FINRA officer or the UPC Committee — previews the structure this dictionary anticipates for FINRA Rules 11892 through 11894: a FINRA officer making an initial determination (presumably under FINRA Rule 11892 or FINRA Rule 11893's category-specific frameworks), with the UPC Committee available for review (under FINRA Rule 11894, consistent with that rule's title).

Supplementary Material .02: FINRA System Disruptions and the Limits of "Simple Assertion"

Supplementary Material .02 establishes the multi-factor standard FINRA applies — in making a determination regarding whether a transaction is clearly erroneous, FINRA takes into account the circumstances at the time of the transaction, the maintenance of a fair and orderly market, and the protection of investors and the public interest.

This three-factor standard — circumstances at the time, fair and orderly market maintenance, and investor/public interest protection — establishes a holistic, context-dependent inquiry rather than a mechanical price-deviation formula. This connects to the broader pattern this dictionary has observed of the UPC Committee's (and, here, FINRA officers') discretionary, circumstances-dependent authority — FINRA Rule 11140(c) and (e)'s late-information fallbacks (whatever date is practical having regard to the circumstances pertaining), and FINRA Rule 11810(g)'s additional-extension authority due to the circumstances involved.

The second and third sentences establish the participant-responsibility and evidentiary-threshold principles — participants in FINRA systems are responsible for ensuring that the appropriate price and type of order are entered into FINRA's systems, and simple assertion by a member that it made a mistake in entering an order or a quote, or that it failed to pay attention or to update a quote, may not be sufficient to establish that a transaction was clearly erroneous. This places the burden of accurate order entry squarely on the entering member, and confirms that a member cannot retroactively unwind an unfavorable execution merely by claiming, after the fact, that the order was a mistake — the obvious error standard from the rule's core definition must be independently evident, not established solely through the member's own post-hoc characterization of its own conduct.

Supplementary Material .03: The Systemic Focus — "Large Numbers of Parties or Trades" and Extraordinary Events

Supplementary Material .03 describes the Rule 11890 Series' general orientation — generally focused on systemic problems that involve large numbers of parties or trades, or market conditions where it would not be in the best interests of the market for one or more transactions to stand.

This systemic framing distinguishes the Rule 11890 Series' typical application from a purely individual-transaction dispute — while the core definition's obvious error standard could, in principle, apply to a single erroneous trade between two parties, Supplementary Material .03 signals that the framework is generally focused on situations with broader market impact: large numbers of parties or trades (for example, a software malfunction generating numerous erroneous orders across many counterparties) or market conditions where allowing transactions to stand would not serve the market's best interests more broadly.

The second sentence extends this systemic focus to extraordinary events — situations where an extraordinary event has occurred or is ongoing that has had a material effect on the market for a security traded over-the-counter or has caused major disruption to the marketplace. This OTC-specific reference — a security traded over-the-counter — anticipates FINRA Rule 11893's OTC Equity Securities-specific framework, suggesting that extraordinary-event scenarios may receive particular attention within that rule's provisions.

Supplementary Material .04: Account Intrusion — The Boundary Between Clearly Erroneous Transactions and Fraud

Supplementary Material .04 establishes an important scope limitation — FINRA's clearly erroneous authority under the Rule 11890 Series does not extend to unauthorized trading activity or attempts to manipulate stock prices by illegally gaining access to legitimate accounts or opening new accounts using false information (often referred to as "account intrusion"). Such suspicious trading activities relate to allegations of fraud and therefore are not within the scope of the Rule 11890 Series.

This boundary is conceptually significant — it confirms that the Rule 11890 Series addresses a categorically different problem from fraud. A clearly erroneous transaction, as the core definition establishes, involves an obvious error in a transaction's terms — a mistake, however it arose. Account intrusion, by contrast, involves a deliberate, unauthorized act — someone illegally accessing another's account, or opening an account under false information, specifically in order to manipulate prices. Even though account intrusion might, in some instances, produce transactions with anomalous prices (resembling, superficially, a clearly erroneous transaction), Supplementary Material .04 confirms that the Rule 11890 Series' remedial mechanisms (price adjustment or cancellation under FINRA Rule 11892 or FINRA Rule 11893, with UPC Committee review under FINRA Rule 11894) are not the appropriate vehicle for addressing such conduct — that conduct instead falls within FINRA's broader fraud-related enforcement authority.

The final sentence's affirmative guidance — members should routinely review the adequacy of their internal controls and ensure that appropriate system safeguards are in place to minimize or eliminate the potential for account intrusion — extends beyond mere scope-limitation into a proactive supervisory expectation, consistent with the broader pattern of member supervisory obligations this dictionary has observed throughout FINRA's rules.

The Absent 2010 Consolidation Amendment

FINRA Rule 11891's amendment history — concluding with SR-FINRA-2009-068 effective February 15, 2010 — is notable for what it does not include: no SR-FINRA-2010-030 or SR-FINRA-2010-060 amendment effective December 15, 2010 appears, in contrast to essentially every other rule this dictionary has examined throughout its coverage of the 11000 series. This dictionary confirms this absence as observed directly from FINRA Rule 11891's amendment history table, without speculating as to its cause — it may simply reflect that FINRA Rule 11891's substantive content (having been adopted via SR-NASD-2002-127 effective January 27, 2003, renumbered via SR-NASD-2003-80 effective May 6, 2003, and most recently amended via SR-FINRA-2009-068 effective February 15, 2010 — itself associated with Notice 10-04, the same January 15, 2010 notice this dictionary encountered on FINRA Rule 11890's own page) was already in its current, Consolidated-Rulebook-appropriate form by February 2010, obviating any need for a further December 2010 amendment of the kind that transferred other Uniform Practice Code provisions into the Consolidated Rulebook framework at that later date.

The Renumbered by SR-NASD-2003-80 effective May 6, 2003 entry confirms that FINRA Rule 11891 occupied a different rule number prior to May 2003 — consistent with this dictionary's observation, in connection with FINRA Rule 11721, that sub-numbered or renumbered positions within the 11000 series sometimes reflect rules added or relocated after an original numbering scheme was established.

Connection to FINRA Rules 2010, 11100, 11110, 11220, 11361, 11362, 11721, 11840, 11890, 11892, 11893, and 11894

FINRA Rule 11891 connects directly and by substantive parallel to FINRA Rule 2010 — Supplementary Material .01's conduct inconsistent with just and equitable principles of trade language directly invokes FINRA's foundational commercial-honor standard, paralleling the cross-referencing technique this dictionary first examined in connection with FINRA Rule 11721. It connects to FINRA Rule 11100(d) and FINRA Rule 11220 — whose CUSIP and description-of-securities frameworks underlie the identification of the security category in the core definition. It connects to FINRA Rule 11110 — whose UPC Committee Supplementary Material .01 names as one of two possible final-decision-makers (alongside a FINRA officer) under the Rule 11890 Series. It connects to FINRA Rules 11361, 11362, and 11840 — whose units-of-trading concepts underlie the number of shares, or other unit of trading category in the core definition. It connects to FINRA Rule 11721 — sharing the FINRA-Rule-2010-cross-reference technique as a structural parallel within this dictionary's coverage. It connects to FINRA Rule 11890 — sharing Notice 10-04 as a directly displayed selected notice on both rules' pages. And it connects directly to FINRA Rules 11892, 11893, and 11894 — the remaining rules of the cluster, for which FINRA Rule 11891's core definition and four Supplementary Material items establish the foundational framework, including the FINRA-officer/UPC-Committee decision-making structure Supplementary Material .01 previews and the OTC-specific extraordinary-event focus Supplementary Material .03 anticipates for FINRA Rule 11893.

Examination Relevance and Key Takeaways

FINRA Rule 11891 is tested on the Series 7 and Series 24 examinations as the foundational definition for the Clearly Erroneous Transactions framework — establishing what constitutes an "obvious error," the enforcement mechanism for FINRA officer and UPC Committee rulings, the multi-factor determination standard, the framework's systemic orientation, and its explicit exclusion of account intrusion and fraud.

The key points to retain are these: FINRA Rule 11891 defines a transaction's terms as "clearly erroneous" when there is an obvious error in price, number of shares or other unit of trading, or identification of the security; Supplementary Material .01 makes refusal to effectuate a final FINRA officer or UPC Committee decision under the Rule 11890 Series itself conduct inconsistent with just and equitable principles of trade — a direct FINRA Rule 2010 parallel to the cross-referencing technique this dictionary examined in FINRA Rule 11721; Supplementary Material .02 establishes a three-factor determination standard (circumstances at the time, fair and orderly market maintenance, investor/public interest protection), places order-accuracy responsibility on participants, and confirms that a member's simple assertion of mistake may not suffice; Supplementary Material .03 describes the Rule 11890 Series as generally focused on systemic problems involving large numbers of parties or trades, or extraordinary events materially affecting an OTC security's market or causing major marketplace disruption; Supplementary Material .04 confirms the framework does not extend to account intrusion or unauthorized trading, which remain fraud matters outside its scope, while encouraging members to maintain adequate internal controls and system safeguards; and the rule was Adopted by SR-NASD-2002-127 effective January 27, 2003, Renumbered by SR-NASD-2003-80 effective May 6, 2003, and amended by SR-NASD-2005-089 effective October 1, 2005, SR-NASD-2006-104 effective March 5, 2007, and SR-FINRA-2009-068 effective February 15, 2010 — notably without a subsequent December 15, 2010 Consolidated Rulebook amendment, an exception to the pattern this dictionary has traced throughout the 11000 series — with two selected notices, 03-11 and 10-04.