Stock Circuit Breaker Implementation

Tomorrow - Friday, June 10, the SEC will implement new circuit breaker rules on all US stock exchanges.

This is what the circuit breaker does: when a stock in the S&P 500 drops 10% in a 5 minute period, there will be a 5 minute trading halt across all exchange platforms for that stock. The new rules are aimed at preventing a repeat of the May 6 "flash crash" in which the Dow Jones industrials lost 1,000 points in less than a half hour.

This is a pilot program for 6 months. For some reason ETFs are not included in this test. I am hopeful that they will be included soon, because an ETF is traded just like a stock and should come under the same rules.