SEC circuit breakers

Additional changes to prevent another "flash crash" are on the way, the U.S. Securities and Exchange Commission said Monday. Among other things, the commission may tinker with the circuit breakers it set up to automatically halt trading if a stock falls 10% in five minutes.

Trading in Cisco Systems shares was briefly halted in late morning trading Thursday, as the shares soared 10% within a few minutes, triggering the market's SEC-mandated cooling-off circuit breakers.