Wall St dives as shutdown worries resurface

A sell-off to end Wednesday's trading session as investors worried record new global infections could lead to further restrictions that will slow the economy.

The Dow lost 344 points. The S&P 500 shed 41 points. The Nasdaq fell nearly 100 points.

A pause after hitting record highs earlier this week and outsized stock gains this year makes sense, says Liz Miller of Summit Place Financial.

"I think we do have stretched valuations for some of the winners so far this year. But it's not that they're not still good companies and still good stocks. I just think we have discounted in an expectation that the way they benefited in this unique environment is going to keep going year after year. And we all know this is a really unique time."

A number of corporate stories failed to keep the broader market afloat.

Boeing received U.S. approval to put the 737 MAX back into the air. Boeing's best-selling jet had been grounded for nearly two years after two fatal plane crashes killed 346 people.

Airline industry analyst Robert Mann:

"If there's reason to celebrate, it's probably for 30 seconds and then it's time to move forward to get the airplane back in the hands of operators. It's a positive issue, clearly, but it's just step one of a very, very long process."

Shares of Boeing gave up early gains to end down by more than 3 percent.

Pfizer said it will apply for emergency authorization for its COVID-19 vaccine after releasing results from a late-stage trial that boasted a 95% effective rate. That stock rallied less than a full percent.

Target smashed quarterly sales expectations. The major discount chain continues to benefit from its quick delivery services, which allows customers to buy online and pick-up in store or have their order brought out to them. Digital sales soared 155 percent - driving profits higher from a year ago. Shares touched an all-time high.

In economic news: new home construction projects stayed at a 13-1/2 year high in October as record-low mortgage rates fuel a housing boom.