WASHINGTON — Early Wall Street reaction to the U.K. referendum vote to leave the European Union was fast and hard. The Dow Jones Industrials Average fell more than 500 points in the first few minutes of trading.

The big decline was expected, and follows a plunge in global commodities markets.

The Dow’s early Friday loss was the biggest one day drop since January 20, 2016.

Wall Street circuit breakers will kick in and halt trading if the drop accelerates.  New York Stock Exchange trading will be halted for 15 minutes if the S&P 500 Index falls 7 percent.

It was down 3 percent in early Friday trading.