Electronic Communications Network is defined in Regulation NMS for the specific purposes of § 242.602(b)(5), with explicit exclusions.
ReviewedEvidence1 sourceSectionPhrases & Idioms
Quick answer
For § 242.602(b)(5), Regulation NMS defines an electronic communications network as a qualifying order-dissemination and execution system, subject to stated exclusions.
Key details
Canonical FormElectronic Communications Network
Core MeaningFor purposes of § 242.602(b)(5), a Regulation NMS-defined electronic system that widely disseminates certain market-maker orders to third parties and permits those orders to be executed against, subject to specified exclusions.
Further guidance
History Boundary
Preserve the explicit § 242.602(b)(5) scope and current exclusions when explaining the term.
Meaning
The current definition is expressly limited to the purposes of § 242.602(b)(5) and includes exclusions for certain crossing systems and certain market-maker-operated systems.
Usage Boundary
Do not present this § 242.600 definition as an all-purpose definition of every system commonly called an ECN.
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.
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.
Affiliate of a Subscriber is a current Regulation ATS defined term. This guide preserves the rule-specific meaning and boundary instead of replacing it with informal market shorthand.
Under current U.S. Regulation NMS definitions, aggregate quotation size is the sum of the quotation sizes of all responsible brokers or dealers communicating bids or offers in an NMS security at the same price. Treat this as a U.S. securities-regulation definition; it should not be generalized to unrelated uses of aggregate size or quotation outside Regulation NMS.
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.
Auction Information is a current Regulation NMS term for specified, publicly disseminated exchange data generated leading up to and during securities auctions.
Under Regulation NMS, an automated quotation is a quotation displayed by a trading center that can be acted on through an automated facility meeting specified immediate-or-cancel response and update conditions. Treat this as a U.S. securities-regulation term. The definition is jurisdiction- and rule-specific, not a general dictionary label for every electronic market quote.
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.
