Dow tumbles 345 points as fresh lockdown measures overshadow vaccine progress

• US stocks fell on Wednesday as new economic restrictions erased morning optimism about coronavirus vaccine news.
• New York City announced on Wednesday afternoon that it would close public schools as positivity rates in the city increase.
• The vaccine being developed by Pfizer and BioNTech was 95% effective at protecting against COVID-19 in patients in a late-stage trial, Pfizer said Wednesday. The firms plan to apply for emergency use authorization on Friday.
• Bitcoin surged above $18,000 before paring some gains. The cryptocurrency's strong momentum has placed it just below its record highs of 2017.
• Watch major indexes update live here.

US equities erased early gains and sank on Wednesday as new restrictions offset hopes for a sooner-than-expected distribution of a coronavirus vaccine.

New York City announced Wednesday afternoon that it would close public schools and transition to online learning beginning Thursday as positivity rates in the city increase.

On Tuesday, the US reported more than 155,800 new COVID-19 cases, and hospitalizations neared 77,000, according to the COVID Tracking Project. The new lockdown measures intensified concerns that surging case counts would freeze the nation's economic rebound.

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

• S&P 500: 3,567.79, down 1.2%
• Dow Jones industrial average: 29,438.42, down 1.2% (345 points)
• Nasdaq composite: 11,801.60, down 0.8%

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The revived virus fears offset bullishness linked to new vaccine progress. Pfizer and BioNTech announced Wednesday morning their vaccine was 95% effective at protecting against COVID-19 in participants in a late-stage trial. Pfizer later said it planned to apply for emergency use authorization in the US on Friday.

While the Food and Drug Administration's vetting process is set to take weeks, the historically quick vaccine development suggests vulnerable populations could receive the shot in early 2021. Pfizer and BioNTech climbed on the news.

Though Pfizer's announcement brought the US even closer to distributing a vaccine, the market's reaction was decidedly less enthusiastic than after past vaccine updates.

"It's been a frantic few weeks, with the hype around the election barely easing off before vaccine euphoria took over," said Craig Erlam, a senior market analyst at Oanda Europe. "Perhaps we're now seeing a little fatigue kicking in ahead of what is likely to be a lively end to the year."

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Consumer-discretionary and industrial stocks eked out mild gains and outperformed the rest of the market. Energy and utilities stocks underperformed.

Boeing fell after leading the Dow higher in the morning. The Federal Aviation Administration said Wednesday that the company's 737 Max jet could fly again after its 20-month grounding.

Zoom spiked after New York City announced its school closure. The stock has repeatedly surged on signs that Americans will resume quarantines and turn back to its videoconferencing service.

Bitcoin surged above $18,000 for the first time in three years before retracing gains. The world's most popular cryptocurrency cleared the $17,000 resistance level on Tuesday, and all eyes are on whether the token can soon clear $20,000 for the first time.

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Gold prices dipped as much as 0.9%, to $1,863.92 per ounce, as the precious metal fell further below its $1,900 support level. The US dollar fell against most major peers, while Treasury yields climbed.

Oil futures rose on the Pfizer news before paring some gains. West Texas Intermediate crude increased as much as 2.5%, to $42.46 per barrel. Brent crude, oil's international standard, climbed 2.6%, to $44.89 per barrel, at intraday highs.

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