Regulation NMS defines trading center broadly to include specified exchanges, association facilities, alternative trading systems, market makers, and other broker-dealers that execute orders internally as principal or crossing agent. This page uses the U.S. Regulation NMS definition; ordinary-language uses of trading center can be broader and should not be substituted for the regulatory term.
ReviewedEvidence1 sourceSectionPhrases & Idioms
Quick answer
In Regulation NMS, trading center is a defined market-structure category covering several kinds of order-execution venues or firms.
Key details
Canonical FormTrading Center
Core MeaningRegulation NMS defines trading center broadly to include specified exchanges, association facilities, alternative trading systems, market makers, and other broker-dealers that execute orders internally as principal or crossing agent.
Further guidance
History Boundary
This page uses the U.S. Regulation NMS definition; ordinary-language uses of trading center can be broader and should not be substituted for the regulatory term.
Meaning
In Regulation NMS, trading center is a defined market-structure category covering several kinds of order-execution venues or firms.
Usage Boundary
This page uses the U.S. Regulation NMS definition; ordinary-language uses of trading center can be broader and should not be substituted for the regulatory term.
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, an “automated trading center” is a trading center with systems, procedures, and rules capable of displaying automated quotations, identifying non-automated quotations as manual, and applying reasonable standards for changes between automated and manual status. This is a condensed rule-scoped explanation of 17 CFR § 242.600; the full definition contains multiple operational conditions and should be consulted for compliance work.
Alternative Trading System is a current federal securities-regulation defined term. This guide preserves the rule-specific definition and boundaries instead of replacing it with informal market shorthand.
Under current U.S. Regulation NMS, “market center” means any exchange market maker, OTC market maker, alternative trading system, national securities exchange, or national securities association. This is the enumerated § 242.600 definition and should not be broadened to every venue, broker, or securities-market participant.
Regulation NMS defines regular trading hours as 9:30 a.m. to 4:00 p.m. Eastern Time, or another time period determined under the referenced rule provision. The definition is regulatory and U.S.-market specific; extended-hours sessions and venue-specific schedules are separate concepts.
A defined Regulation NMS facility operated by or for an exchange or national securities association that executes orders or presents them to members for execution. This page is limited to the Regulation NMS definition; other regulatory or operational uses of “trading facility” may be broader.
Trading Rotation is a current federal securities-regulation defined term. This guide preserves the rule-specific definition and boundaries instead of replacing it with informal market shorthand.
Actionable Indication of Interest is a current federal securities-regulation defined term. This guide preserves the rule-specific definition and boundaries instead of replacing it with informal market shorthand.
Administrative Data is a current Regulation NMS defined term for specified administrative, control, and technical messages in the market-data plan framework.
