US stock exchanges will have to test trading systems, report problems under new SEC rules

U.S. stock exchanges will have to keep a closer eye on their electronic trading systems under rules adopted by federal regulators.

The Securities and Exchange Commission voted 5-0 Wednesday to require routine testing of exchanges' trading systems. The exchanges also will be required to notify the SEC about problems, including any systems that are compromised by hacking. Any problems must be quickly corrected.

The SEC action follows a series of technical disruptions in recent years — notably the "flash crash" of May 2010 — that regulators say shook investors' confidence in the markets.

The rules will replace a 20-year-old voluntary program for U.S. exchanges, which include the New York Stock Exchange, Nasdaq and a host of competing electronic marketplaces. They are intended to reduce the chances of technology problems occurring.