# 2026-19220: MX2 LLC Joins Stock Trade Watchdog: CAT Now Has a New Kitten

2026-19220, Joint Industry Plan; Notice of Filing and Immediate Effectiveness of Amendment to the National Market System Plan Governing the Consolidated Audit Trail To Add MX2 LLC as a Participant, is a Federal Register notice from Securities and Exchange Commission published 2026-09-21, effective 2026-09-03 (as of 2026-09-28).

- Canonical: https://policyrisk.com/federal-register/2026-19220
- As of: 2026-09-28
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2026-19220
- Title: Joint Industry Plan; Notice of Filing and Immediate Effectiveness of Amendment to the National Market System Plan Governing the Consolidated Audit Trail To Add MX2 LLC as a Participant
- Type: Notice
- Agencies: Securities and Exchange Commission
- Citation: 91 FR 59822
- Published: 2026-09-21
- Effective: 2026-09-03
- Comments close: not stated
- Significant: no
- Touches household money: no
- Regulation identifier numbers: none
- Last updated: 2026-09-28

## In one line

MX2 LLC Joins Stock Trade Watchdog: CAT Now Has a New Kitten

## Summary

MX2 LLC just joined the big league as a new participant in the Consolidated Audit Trail (CAT) system, which tracks stock trades across the U.S. This means MX2 will now help keep the market fair and transparent alongside other major exchanges. The change took effect right away on September 3, 2026, with no extra costs announced for the public.

## Effects PRIA read

No economic effects identified for this document.

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## Sources
- [2026-19220 on federalregister.gov](https://www.federalregister.gov/documents/2026/09/21/2026-19220/joint-industry-plan-notice-of-filing-and-immediate-effectiveness-of-amendment-to-the-national-market)
- [2026-19220 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-09-21/pdf/2026-19220.pdf)

## Related
- [Previous: 2026-19219, Self-Regulatory Organizations; Nasdaq Texas, LLC; Notice of Filing and Immediat…](https://policyrisk.com/federal-register/2026-19219)
- [Next: 2026-19221, Notice of Supplemental Funding, Rural Quality Improvement Technical Assistance…](https://policyrisk.com/federal-register/2026-19221)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2026-19220 (as of 2026-09-28).