US stocks waver as investors weigh vaccine distribution against new lockdown measures

• The S&P 500 and Dow Jones industrial average erased morning gains and closed lower on Monday as investors mulled vaccine distributions, stimulus progress, and the possibility of new economic restrictions.
• A bipartisan $908 billion stimulus proposal is set to be formally unveiled after markets close. The bill is expected to be split into two packages: one with funds for highly supported measures, and a smaller package with more controversial elements.
• US deliveries of Pfizer and BioNTech's coronavirus vaccine began on Monday, marking a major step forward in fighting the pandemic.
• Yet the likelihood of new lockdown measures grew. New York City Mayor Bill de Blasio cautioned that the city should prepare for another full shutdown to slow the virus's spread.
• Watch major indexes update live here.

US stocks erased morning gains and closed lower on Monday as investors weighed stimulus progress and vaccine distribution against dire new restrictions.

The language of a bipartisan $908 billion relief package is set to be introduced Monday afternoon, and Congress is aiming to pass a government funding bill before the week is out.

The relief package will be split into two measures, a source familiar with the matter told Reuters. A $748 billion proposal will have funds for strongly supposed programs, such as small-business aid and expanded unemployment benefits. A separate measure will have aid for state and local governments and liability protections for businesses, critical sticking points that have held back a relief package for weeks.

"There's no way, no way that we are going to leave Washington without taking care of the emergency needs of our people," Democratic Sen. Joe Manchin told Fox News on Sunday.

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

• S&P 500: 3,647.49, down 0.4%
• Dow Jones industrial average: 29,861.55, down 0.6% (184 points)
• Nasdaq composite: 12,440.04, up 0.5%

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Index futures gained early Monday as the first doses of Pfizer and BioNTech's COVID-19 vaccine were delivered in the US. Regulators on Friday approved the vaccine for emergency use, marking a major step forward in fighting the pandemic.

The US Food and Drug Administration is also set to begin evaluating Moderna's vaccine this week, setting the stage for an emergency use authorization before the end of the year.

Yet soaring case counts across the country threaten to further damage the economy before vaccination is widespread. The US reported 186,884 new cases on Sunday, according to The COVID Tracking Project. Deaths climbed above 291,000.

Expectations for a harsh winter battle against the virus lead some cities to reinstate lockdown measures in hopes of slowing its spread. New York City Mayor Bill de Blasio warned that residents should prepare for another full shutdown.

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Stocks last week posted their first weekly loss since early November. The threat of a government shutdown and rising coronavirus cases dragged equities lower on Friday.

Tech stocks outperformed the broader market, leading the Nasdaq composite to notch a healthy gain. Energy and financial names underperformed.

AstraZeneca slid after agreeing to buy Alexion Pharmaceuticals for $39 billion.

DoorDash and Airbnb both tumbled as analysts turned less bullish toward the newly public stocks. The companies each received downgraded ratings, with analysts warning investors that the companies' elevated stock prices leave little room for error.

Virgin Galactic fell after canceling its first manned test flight because of a failed rocket ignition. Shares had gained in recent sessions amid rising hopes for the test.

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Bitcoin reached a 24-hour high of $19,323.17. The cryptocurrency has wavered at about the $19,000 level after soaring close to a record high of nearly $20,000 earlier this month.

Gold slid as much as 1.1%, to $1,818.90 per ounce. The US dollar weakened against all Group-of-10 currency peers, and Treasury yields rose.

Oil prices climbed after a tanker exploded in a Saudi Arabian port. West Texas Intermediate crude gained as much as 1.9%, to $47.44 per barrel. Brent crude, oil's international benchmark, rose 1.7%, to $50.80 per barrel, at intraday highs.

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