U.S. stock benchmarks on Monday closed sharply, with all three indexes posting their worst daily losses in months, amid growing worries about the economic implications of a rising death tolls and growing infections from a fast-moving virus in China.

The Dow Jones Industrial Average DJIA, -0.87% slid 453.93 points, or 1.6%, to 28,535.80, following an intraday nadir at 28,440.47, while those for the S&P 500 index SPX, -1.11% slid 51.84 points, or 1.6%, to 3,243.63, with a Monday low at 3,234.50. The Nasdaq Composite Index COMP, -1.07% shed 175.60 points, or 1.9%, to reach 9,139.31, after hitting a low at 9,088.04.

For the Dow and S&P 500, the daily decline represented the worst daily drops since Oct. 2, and the sharpest daily decline for the Nasdaq Composite since Aug, 23, according to Dow Jones Market Data.

The Dow has now fallen for five straight days, representing its longest losing streak since August.

Worries about the spread of the China virus drove stocks to their lowest levels in over a week on Friday. Last week, the Dow lost 1.2%, while the S&P 500 gave back 1% and the Nasdaq fell 0.8%.

What’s drove the market?

The coronavirus injected Wall Street investors with fresh worries after China extended this week’s Lunar New Year holiday and took more drastic measures to halt the spread of the illness.

As of Monday, the death count rose to more than 80, and the number of those infected neared 3,000 confirmed cases, according to reports. In the U.S., at least 110 people were identified as under investigation for the virus, according to the Centers for Disease Control and Prevention, while a handful of infections were reported in other countries, such as France and Japan.

Read:Coronavirus and Mideast tensions aren’t the stock market’s biggest problems this week, strategist warns

Questions were being raised over the effectiveness of the quarantine on places like Wuhan, China, believed to be the epicenter of the virus. U.S. President Donald Trump on Monday offered China “any help” needed to help control a coronavirus outbreak.

Wuhan’s mayor Zhou Xianwang said that 5 million of the city’s 11 million people had left the city before the travel ban was imposed. As well, reports that the virus may be infectious during its roughly 14-day incubation period may make containment more challenging.

Concerns have been growing about the potential impact of the virus on China’s economy, which is set to slow to around 5.7% in 2021 from 6.1% last year, down from its near double-digit growth when the severe acute respiratory syndrome, or SARS, hit in 2002-03, according to data from the International Monetary Fund.

Some analysts make the case that fears over the coronavirus could provide investors with a catalyst to sell after a torrid 2019 rally.

“We’re being told the market is selling off because of the coronavirus. I think there is a little bit more to it than that,” Robert Pavlik, chief market strategist at SlateStone Wealth. “I think it’s people looking for a reason to take some short-term profits,” he told MarketWatch. “I think this is going to turn out to be an overreaction.”

Sahak Manuelian, managing director of equity trading at Wedbush Securities, pointed to a “negative risk-off mentality” in equities globally, but also thinks investors will focus on corporate earnings as more businesses report fourth-quarter results.

“A lot of attention is going to be on what kind of full-year 2020 guidance is going to be given,” he told MarketWatch.

Nearly half of the 30 Dow components are slated to report results this week from the holiday season, potentially marking the biggest test for the blue-chip index in many years.

In economic news, sales of newly constructed homes in the U.S. dropped 0.4% monthly in December to a seasonally adjusted annual rate of 694,000, the government reported Monday.

“Despite the softer than expected report, we expect that pace of new home sales to pick up in early 2020, supported by rises in inventory and strong demand,” wrote a team of economists led by Oxford Economics’ Nancy Vanden Houten, in a client note.

Check out: These U.S. stocks are down the most as the coronavirus spreads

Also see: The first stock-market ‘correction since October has begun,’ says Morgan Stanley analyst who called 2018 tech rout

Which stocks were in focus?

Shares of AbbVie Inc. ABBV, +0.53% ended 0.6% higher in trading on Monday after the drugmaker said Allergan US:AGN, which it is in the process of acquiring, plans to divest two therapies. Shares of Allergan were up 0.4%.

Arconic Inc. ARNC, -0.75% said Monday it had net income of $309 million, or 70 cents a share, in the fourth quarter, up from $218 million, or 44 cents a share, in the year-earlier period. Shares of the company gained 5.4%.

Marathon Petroleum Corp. MPC, +0.49% said Monday it will raise it quarterly dividend by 9.4%, to 58 cents a share from 53 cents. Shares lost 3.3%.

Shares of vaccines makers and diagnostic companies were active, amid coronavirus fears. Co-Diagnostics Inc. CODX, +3.56% , up 82.5%; NanoViricides Inc. NNVC, -0.92% , up 87%; Allied Healthcare Products Inc. AHPI, +3.40% , closing 50% higher; Inovio Pharmaceuticals Inc. INO, +8.48% , gained 26%; and Novavax Inc. NVAX, -6.19% , advanced almost 9%.

How did other markets perform?

The yield on the 10-year U.S. Treasury note TMUBMUSD10Y, 0.701% tumbled 7.5 basis points to 1.605%, putting the benchmark bond’s rate less than 40 basis points away from its all-time low of 1.32% on June 2016.

West Texas Intermediate crude for March delivery US:CLH20, slid $1.05, or 1.9%, to settle at $53.14 a barrel on the New York Mercantile Exchange, a more than 3-month low, amid fears that China’s deadly influenza could hurt global energy demand.

Bullion prices also shot to a more than six-year high, with gold for February US:GCG20 on Comex adding $5.50, or 0.4%, to settle at $1,577.40 an ounce, after hitting an intraday high of $1,588.40.

While most Asian markets were closed for the Lunar New Year, the Nikkei 225 index NIK, +0.17% closed down 2% and crude oil US:CLH20 fell over 2% as well, while demand for perceived safe-haven assets rose.