By Robert Cook, President and CEO, FINRA. The Consolidated Audit Trail, or CAT, is an SEC-mandated reporting system that collects data regarding trading in the U.S. equities and options markets. The SEC first proposed CAT in 2010 when the limitations of pre-CAT reporting facilities were highlighted by the Flash Crash. The final CAT rule was adopted by the SEC in 2012, a more detailed plan for CAT was approved by the SEC in 2016, and reporting into CAT was implemented in phases from 2018 to 2024.