Markets: Wall Street continues wild swings with big drops.

Fear dominated financial markets again Thursday, and stocks fell sharply on worries about the fast-spreading virus outbreak. It’s the latest shudder in Wall Street’s most volatile week in more than eight years.

Major U.S. indexes lost roughly 3.5%, and Treasury yields touched more record lows in their latest yo-yo move. The slide nearly wiped out the surge stocks had ridden just a day earlier, which came in part on hopes that moves by authorities around the world could cushion the economic fallout.

These vicious swings are likely to continue, as long as the number of new infections continues to accelerate, many analysts and professional investors say. Thursday was the fourth consecutive day where the S&P 500 moved at least 2%.

The growing understanding that the spread of infections — and resulting damage to the U.S. economy — may not slow anytime soon is pulling sharply on markets.

The yield on the 10-year Treasury note went as low as 0.901% for the first time in history, according to Tradeweb. Tumbling yields have brought the average rate on a 30-year fixed mortgage to a record low of 3.29%.

“It’s been a roller-coaster market in recent days for equity investors, and today we appear to be on the downward leg for that ride,” said Terry Sandven, the chief equity strategist at U.S. Bank Wealth Management. “What you need is time, and unfortunately that is still going to result in volatility.”

In China, where the number of new infections has been slowing drastically, stocks trading in Shanghai have rallied nearly 12% since hitting a bottom on Feb. 3. Factories there are gradually reopening, and a return to a sense of normal life may even be on the horizon.

But elsewhere in the world, the mood is darker. There are about 17 times as many new infections outside China as in it, according to the World Health Organization.

In the U.S., the death toll climbed to 12 because of the virus. California declared a statewide emergency, Facebook is temporarily closing a Seattle office after a worker there was diagnosed with the virus, and an industry group said the outbreak could cost airlines as much as $113 billion in lost revenue.

The S&P 500 fell 106.18 points, or 3.4%, to 3,023.94. It’s now 10.7% below the record high it set Feb. 19. The Dow Jones industrial average slumped 969.58 points, or 3.6%, to 26,121.28, and the Nasdaq lost 279.49 points, or 3.1%, to 8,738.60.

Losses were widespread, and energy stocks in the S&P 500 dropped to their lowest level since March 2009.

Travel-related companies continued to fall sharply on worries that frightened customers won’t want to confine themselves in planes or boats with others. Royal Caribbean Cruises sank 16.3%, Carnival fell 14.1% and American Airlines Group lost 13.4%.

This week, the S&P 500 has gone from a jump of 4.6% on Monday, to a loss of 2.8%, and back to a rise of 4.2%. In normal times, a move of even 1% would be notable.

Many economists expect the European Central Bank to make some kind of move in hopes of supporting markets before its March 12 meeting.

The yield on the 10-year Treasury sank to 0.91% from 0.99% late Wednesday. Gold climbed $25.00 to $1,668.00 per ounce as investors piled into investments seen as safe.

Benchmark U.S. crude lost 88 cents to settle at $45.90 per barrel. Brent crude, the international standard, fell $1.14 to $49.99 per barrel.