Stocks fell sharply on Wall Street today, knocking nearly 400 points off the Dow Jones Industrial Average.

The benchmark S&P 500 had its worst day in a week as the sell-off put the market deeper into the red for August. The selling was widespread, with technology companies and banks accounting for a big share of the decline.

Investors sought safety in U.S. government bonds, sending their yields tumbling. The price for gold, another traditional safe-haven asset, closed higher.

The costly trade war between the U.S. and China has rattled markets this month. An escalation in tensions between the world’s largest economies has stoked worries that the long-running trade conflict will undercut an already slowing global economy.

“Trade and the concern that as this escalates it continues to wear on confidence to a point that this actually causes a recession, that’s what people are wrestling with,” said Ben Phillips, chief investment officer at EventShares.

The latest wave of anxious selling left the S&P 500 index down 35.56 points, or 1.2%, at 2,883.09. The Dow fell 389.73 points, or 1.5%, to 25,897.71. The average was briefly down 462 points.

The Nasdaq composite dropped 95.73, or 1.2%, to 7,863.41. The Russell 2000 index of smaller-company stocks lost 18.58 points, or 1.2%, to 1,494.46.

The major indexes are down more than 3% for August. Even after this month’s stumble, they are up solidly this year, led by the Nasdaq with a gain of 18.5%. The S&P 500 is up 15%, though it’s down 4.7% from its all-time high set at the end of July.

Anxiety and fear over the U.S.-China trade war continues to hover over the market and has taken stocks on a wild ride in August.

The S&P 500 index zoomed up and down last week, ending with its second straight weekly loss. The wild swings follow President Donald Trump’s threat to impose more tariffs on Chinese goods, followed by China’s move to allow its currency to weaken.

Trump has promised 10% tariffs on some $300 billion in Chinese imports that haven’t already been hit with tariffs of 25%. The new tariff would go into effect Sept. 1 and more directly affect U.S. consumers.

Last week, Trump said he’d be “fine” if the U.S. and China don’t go ahead with a meeting next month, dampening investors’ hopes for a path to resolving the economically damaging trade war.

The longer the trade conflict drags on, the more it has the potential to threaten the weakening global economy by discouraging trade and causing businesses to pull capital spending plans on hold. The International Monetary Fund expects world trade to slow in 2019 for a second straight year.

“We’re hearing from management teams that there’s just caution on investing, especially globally,” Phillips said. “Multinationals are being very cautious. … Their view is if the rest of the world slows down, the U.S. won’t be insulated from that.”

Traders continued to shift money into bonds today, sending bond prices sharply higher. That pulled down the yield on the 10-year Treasury to 1.64% from 1.73% late Friday, a big move. The yield is used as a benchmark for interest rates on mortgages and other consumer loans.

The drop in bond yields weighed on financial sector stocks. Bank of America fell 2.4% and Citigroup gave up 2.7%. Credit card issuer Synchrony Financial slid 3.9% and Capital One Financial dropped 2.3%.

Technology, health care and consumer discretionary sector stocks accounted for much of the market’s decline. Symantec dropped 5.7%, Nektar Therapeutics slumped 11.2% and Tractor Supply fell 4.7%.

Real estate and utilities stocks posted the smallest declines. Traders usually seek the shelter of utilities and bonds when they want a more secure place to put their money because of concerns over economic growth.

Sysco rose 3.1% after the food distributor beat Wall Street’s fiscal fourth quarter profit forecasts. The company’s revenue edged higher on growth from its U.S. operations.

Shares in Viacom and CBS fell amid published reports suggesting the entertainment companies are close to a merger deal. Viacom slid 4.9% and CBS lost 1.8%.

Major stock markets outside the U.S. were mixed today, with indexes in Europe closed broadly lower while those in Asia ended broadly higher.

Hong Kong’s Hang Seng lagged and shed 0.4% as that city continues to deal with increased tensions from pro-democracy protests. The Hong Kong airport shut down today when thousands of demonstrators occupied its main terminal.

Stocks in Argentina plummeted and the Argentinian peso fell sharply following a primary victory for a populist ticket in the nation’s presidential elections. The nation is in a deep economic crisis and the potential for a drastic change in leadership is rattling investors there.

Matías Carugati, chief economist for Management & Fit, said the victory of the populist Alberto Fernández team would put “sustained” pressure on the exchange rate and stocks due to the prospect that the nation could shift course to a more state-interventionist course for the economy.

Investors are facing a relatively slow week as far as economic reports and corporate earnings. The Labor Department will release its consumer price index for July on Tuesday and Commerce Department will release last month’s retail sales results on Thursday.

Macy’s reports quarterly results on Wednesday and Walmart will report results on Thursday. They are among the last major companies to report their earnings for the latest quarter.

Energy futures were mixed. Benchmark crude oil rose 43 cents to settle at $54.93 a barrel. Brent crude oil, the international standard, added 4 cents to close at $58.57 a barrel.

Wholesale gasoline was unchanged at $1.67 per gallon. Heating oil was also unchanged at $1.81 per gallon. Natural gas fell 1 cent to $2.12 per 1,000 cubic feet.

Gold rose $8.70 to $1,505.30 per ounce, silver rose 14 cents to $17.04 per ounce and copper was unchanged at $2.58 per pound.

The dollar fell to 105.27 Japanese yen from 105.57 yen on Friday. The euro strengthened to $1.1219 from $1.1207.