US stocks have the worst day of 2017

S&P tumbles -1.81%. Dow down -1.77%. The Nasdaq loses 2.57%. OUCH!
The US stocks are ending the day with the largest declines on the year.
The S&P is closing below the 50 day MA for the first time since the French round 1 election gap higher, and also below a trend line on the daily chart at 2359.88 ().