If your outdoor AC unit isn't turning on, check these switches, levels, and lines yourself, before calling for professional ...

The trading curbs go into effect when the S&P 500 crosses certain thresholds during extreme market volatility.

Circuit breakers have become a feature of the stock market that halt trading across exchanges when the S&P 500 falls rapidly. They were born out of the "Black Monday" stock-market crash of 1987 and ...