The Securities and Exchange Commission approved rules to expand the new circuit breaker program to include the Russell 1000 stocks and certain exchange-traded funds. Financial Industry Regulatory Authority and national securities exchanges asked for the changes to the program, which was approved in June and in response to the market upheaval of May 6. The circuit breaker program, which already applies to the S&P 500, halts trading of a stock for five minutes when a 10% price change occurs. The pilot program is effective through Dec. 10. “These circuit breakers and this more objective guidance on breaking erroneous trades will help our markets retain the confidence of investors and companies,” said SEC Chairman Mary Schapiro. “We have worked quickly with the exchanges to take these steps, and we will continue to be very focused on addressing weaknesses exposed on May 6.” The Russell 1000 includes most of the largest publicly traded companies in the U.S. that combined account for more than 90% of total market capitalization of all domestic stocks. Financial firms such as Annaly Capital, the Apollo Group, CoreLogic, Fiserv and Simon Property Group list on the Russell exchange. Write to Jason Philyaw.