The Dow Jones Industrials dumped 151.94 points to pause for noon at 38,753.72.
The much-broader skidded 34.19 points to 5,116.29.
The NASDAQ slipped 158.13 points, or 1%, to 15,970.40.
Despite the moves downward, the Dow and S&P 500 are still tracking to end the week up around 0.5%, while the NASDAQ is on pace to add 0.3%. All three are also higher on the year.
Tech shares were broadly lower, with Apple and Microsoft down more than 1%. Shares of Amazon and Google-parent Alphabet also fell. Nvidia bucked the trend, however, climbing more than 1%. The chipmaker has whipsawed this week as traders worry about the stock’s valuation and book profits in the high-flying name.
Trading volumes will be elevated and prices may be volatile Friday as futures and options on stock indexes and individual stocks all expire simultaneously in a process known as “triple witching” that happens once a quarter.
Prices for the 10-year Treasury lost ground, boosting yields to 4.30% from Thursday’s 4.29%. Treasury prices and yields move in opposite directions.
Oil prices skidded 24 cents to $81.02 U.S. a barrel.
Gold prices sagged $3.30 to $2,164.20.