On September 10, the Securities and Exchange Commission (SEC) approved new rules to expand its circuit breaker pilot program, which currently applies to stocks listed in the S&P 500 Index, to all stocks in the Russell 1000 Index and certain exchange-traded funds. As we discussed in our post of May 19, the SEC's circuit breaker is tripped and stops trading in a security for a five-minute period if the security experiences a 10 percent price change over the preceding five minutes.

The SEC also approved rules clarifying the process for breaking erroneous trades. We discussed generally the nature of the SEC's original proposal in our post of June 18.