The Securities and Exchange Commission on Thursday gave final approval to the combination of the two organizations charged with regulating the New York Stock Exchange and the Nasdaq Stock Market.

The SEC announced its approval of rule changes that allow for the creation of a single self-regulatory organization, to be known as the Financial Industry Regulatory Authority, or FINRA. It’s one of the biggest changes in the system governing policing of the U.S. securities markets since its creation 72 years ago.