SEC Opens Broad Review of CAT and Other Market Audit Trails

The U.S. Securities and Exchange Commission said on April 16 that it is seeking public comment through a concept release as part of a comprehensive review of the Consolidated Audit Trail, or CAT, along with other audit trails and related data sources used in securities-market regulation.

That is an important signal even though it is not an immediate rule change. CAT was built to help regulators track orders and executions across U.S. equity and options markets, but it has been controversial for years because of its cost, scope, and data-governance implications. By reopening the discussion in a formal comment process, the SEC is signalling that market-surveillance architecture is back on the table.

Why it matters

For traders, CAT is mostly a back-end issue until it changes the economics or operational rules around market access. But those back-end systems shape how broker-dealers report activity, how exchanges and regulators reconstruct trading events, and where compliance costs land. If the review leads to narrower data collection, lower costs, or a different surveillance mix, the effects can flow through to brokers and eventually to customer pricing.

What to watch next

The next step is the comment process itself. Watch for exchanges, brokers, market makers, and investor groups to argue over costs, privacy, and whether the current audit-trail stack is proportionate to the oversight benefits regulators say it delivers.