Midpoint-or-Better Limit Order is a current Regulation NMS defined term. This guide keeps the non-marketable requirement, side-specific midpoint test, and determination-time conditions together.
ReviewedEvidence1 sourceSectionPhrases & Idioms
Quick answer
Under Regulation NMS, a midpoint-or-better limit order is a qualifying non-marketable buy order at or above the NBBO midpoint or sell order at or below it, determined at the rule-specified time.
Key details
Canonical FormMidpoint-or-Better Limit Order
Core MeaningA non-marketable limit order priced at or better than the midpoint of the national best bid and offer for the relevant side, using the rule-specified determination time.
Further guidance
History Boundary
This page reflects the current reviewed 17 CFR § 242.600 definition and should be rechecked if Regulation NMS changes.
Meaning
17 CFR § 242.600 defines midpoint-or-better limit orders as qualifying non-marketable buy orders at or above the NBBO midpoint and qualifying non-marketable sell orders at or below that midpoint.
Usage Boundary
The definition includes timing provisions for periods when the NBBO is unavailable or the primary listing market has not yet disseminated its first firm, uncrossed quotations.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
Under current U.S. Regulation NMS, a “customer limit order” is an order to buy or sell an NMS stock at a specified price that is not for a broker or dealer account, and it includes an order transmitted by a broker or dealer on behalf of a customer. Keep this definition tied to NMS stock, a specified price, and the rule’s express inclusion of orders transmitted by a broker or dealer on behalf of a customer.
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Under current U.S. Regulation NMS, a “non-marketable limit order” is any limit order other than a marketable limit order. Keep this definition tied to 17 CFR § 242.600; whether an order is marketable depends on the rule’s marketability framework and should not be generalized from the label alone.
Average Midpoint is a current Regulation NMS defined term. This guide preserves the share weighting and timing rules instead of reducing it to an ordinary arithmetic midpoint.
Under current U.S. Regulation NMS, a “bid or offer” is the bid price or offer price communicated by an exchange or association member to a broker, dealer, or customer at which it is willing to buy or sell one or more round lots of an NMS security as principal or agent; indications of interest are excluded. Keep this definition tied to 17 CFR § 242.600; everyday uses of bid and offer and other market-rule definitions can differ.
Categorized by Order Size is a current Regulation NMS defined term. This guide keeps the reporting classification tied to the enumerated rule buckets rather than informal size labels.
