Consolidated Audit Trail (CAT)
The Consolidated Audit Trail (CAT) was established by the SEC to enable regulators to track all order and trading activity across U.S. markets for listed equities and options. Operated by 25 Self-Regulatory Organizations (SROs), including equity and options exchanges, and under SEC supervision, the CAT is designed to strengthen market oversight and transparency by providing a comprehensive view of trade data.
The securities industry worked diligently to design and implement CAT reporting systems. The transaction database became fully operational in December 2021, marking a major milestone in market surveillance infrastructure.
Key Focus Areas
Enhancing Privacy and Data Security
SIFMA has long raised concerns about the collection and storage of personally identifiable information (PII) in the CAT’s Customer and Account Information System (CAIS). We have consistently proposed viable alternatives that would achieve regulatory objectives while mitigating privacy and cybersecurity risks to investors.
On February 10, 2025, the SEC issued an exemptive order relieving firms of the requirement to report certain PII – an appropriate and long-overdue step that SIFMA strongly supported. In March 2025, CAT LLC filed an amendment to further reduce the amount of customer data collected. SIFMA also supported the SEC’s September 2025 order to reduce CAT operating costs, aligning with our advocacy for secure and cost-effective implementation.
Ensuring Secure Use and Governance of CAT Data
SIFMA continues to engage with the SEC on its August 2020 data security proposal, which would prohibit bulk downloading of CAT data and restrict any use of the data for commercial purposes. We support clear, enforceable limits on data access and use, and continue to advocate for strong cybersecurity protections across all stages of CAT data collection and retention.
Advancing a Fair and Transparent Funding Model
The current CAT funding model, submitted by the SROs, lacks balance and transparency. SIFMA continues to advocate for a collaborative, equitable cost-allocation framework that reflects the shared responsibilities of regulators and market participants. We have recommended that the Commission disapprove the proposed model in its current form and work toward a sustainable approach that minimizes costs to investors.
CAT Implementation Timeline: Key Milestones
- March 18-June 27, 2019: CAT registration period
- September 30, 2019: Connectivity testing begins
- December 16, 2019: Industry testing begins
- June 22, 2020: Initial equities reporting for large and small broker-dealers (OATS reporters)
- July 20, 2020: Initial options reporting for large broker-dealers
- Dec. 13, 2021: Full equities and options reporting for large and small broker-dealers
- July 11, 2022: Full customer and account reporting for large and small broker-dealers
- May 31, 2024: Customer and Account Information System (CAIS) live
The Bottom Line
The Consolidated Audit Trail plays an important role in regulatory oversight of U.S. equity and options markets. SIFMA supports its mission while continuing to advocate for robust data protections, cost-effective operations, and balanced governance to ensure the CAT serves investors and markets securely and efficiently.
