CNBC Alert: Dow Jones Industrial Average Down Over 180 Points; Nasdaq and S&P 500 Off More Than 1.4%

Not a great day to be in the market.

3:40 EST Update: Dow Down Over 200 Points As Trading Curbs Imposed; Nasdaq and S&P 500 Are Off More Than 1.6%

What exactly is a trading curb? I had to look this up myself. From Wikipedia:

A trading curb, also known as a circuit breaker, is a point at which a stock market will stop trading for a period of time in response to substantial drops in value.

A trading curb is described as a circuit breaker. I guess it tripped this afternoon…