Jianan Yu/Reuters

US stocks declined on Tuesday as investors weighed a longer-than-expected recovery from the escalating coronavirus outbreak.

The weak trading came as major banks revised their second-quarter GDP projections lower, citing a record jump in unemployment claims and severe financial tightening.

The Dow Jones industrial average completed its worst first quarter in history, while both the Dow and S&P 500 turned in their worst monthly returns since the financial crisis.

Global confirmed COVID-19 cases passed 800,000 on Tuesday, and the death toll climbed above 39,000. The US death toll passed 3,000 after 500 people died in 24 hours.

Watch major indexes update live here.

US stocks declined on Tuesday as traders weighed a longer-than-expected recovery from the escalating coronavirus outbreak.

The losses came as numerous economists across Wall Street further revised their quarterly gross-domestic-product estimates lower amid the pandemic.

The market close saw the Dow Jones industrial complete its worst first quarter in history, having tumbled 23%. In addition, both the Dow (-14%) and S&P 500 (-12%) turned in their worst monthly returns since the depths of the financial crisis in October 2008.

Here's where the major US indexes stood at the 4 p.m. ET market close on Tuesday:

Read more: Bank of America examined the stock market during every recession since 1929 and concluded the recent meltdown is not over. Here's its trading strategy for a deeper crash.

On a GDP basis, Goldman Sachs sees the economy shrinking by 34% next quarter, eclipsing its previous projection of 24%. The firm added on Tuesday that "sky-high" jobless claims hinted at a "bigger output and (especially) labor market collapse than we had anticipated."

JPMorgan on Thursday lowered its estimate to a 25% GDP contraction as the outbreak tightens financial conditions across the country.

Markets may finally be stabilizing after more than a month of decade-high volatility, but investors should still be wary in deploying their cash, Randy Frederick, vice president of trading and derivatives at the Schwab Center for Financial Research, told Markets Insider in an interview. Any investors buying in after single-day gains likely lost massive amounts of capital through March, as the jumps were often followed by massive declines in the next session.

The recent streak of market wins gives traders only a suggestion of a bullish trend in equities, Frederick said.

"I always caution that two consecutive up days is your first sign that it might be safe to do some bargain hunting, it's not the 'all-clear' flag," he added.

Oil gained on Tuesday morning after closing at 18-year lows the prior day. Brent crude, oil's international benchmark, has seen unprecedented price pressure from the coronavirus outbreak's hit to global demand.

A price war between Saudi Arabia and Russia has further dragged prices lower as the two giants flood the market with unwanted inventory. The average US gallon of gas slipped below $2 for the first time in four years, according to a Tuesday AAA report.

The total number of coronavirus infections passed 800,000 on Tuesday as the global death toll passed 39,000. The US death toll climbed above 3,000 on Tuesday after 500 people died in 24 hours.

Read more: RBC says coronavirus-battered stocks could plunge another 28%. Here are the areas of the market they say will thrive when the dust clears.

Some firms are pointing out oversold areas of the market that could prove fruitful in the wake of new Federal Reserve measures and accelerated sell-offs.

Stocks with strong balance sheets and cash generation power present "an enormous opportunity" for investors seeking value in markets' low prices, Solita Marcelli, deputy chief investment officer for the Americas at UBS, said in a note to clients. Emerging-market debt is also poised to gain from the Fed's new repo facility, she added.

Investors should focus on the long-term now more than ever, Keith Banks, Bank of America's vice chair and head of investment solutions, said in a Tuesday appearance on CNBC. Volatility can drive traders to do "the wrong thing at the wrong time," and holding assets through a coronavirus recovery is the best way to play the swinging market.

"I think a lot of people are trying to get clever right now and time the market," he said. "The reality is, it's time in the market, not timing the market."

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