An escalating showdown between the U.S. and China over trade sent shudders through the stock market Tuesday, handing the S&P 500 is biggest loss since late March.

Technology and industrial stocks, which would stand to suffer greatly in a protracted trade war, led the way lower. The U.S. was set to impose higher tariffs on China on Friday, a day after representatives from both nations are scheduled to resume trade talks in Washington.

On Tuesday:

The S&P 500 index slumped 48.42 points, or 1.7%, to 2,884.05.

The Dow Jones Industrial Average lost 473.39 points, or 1.8%, to 25,965.09.

The Nasdaq composite fell 159.53 points, or 2%, to 7,963.76.

The Russell 2000 index of small company stocks gave up 32.66 points, or 2%, to $1,582.31.

For the week:

The S&P 500 is down 61.59 points, or 2.1%.

The Dow is down 539.86 points, or 2%.

The Nasdaq is down 200.24 points, or 2.5%.

The Russell 2000 is down 31.71 points, or 2%.

For the year:

The S&P 500 is up 377.20 points, or 15%.