By Twesha Dikshit and Purvi Agarwal

(Reuters) -Wall Street's main indexes fell on Thursday, as technology stocks came under fresh selling pressure, while U.S. tariff concerns and uncertainty around the health of the economy kept investors on edge.

Most tech stocks declined as worries over stretched valuations lingered, after a brief respite on Wednesday. Warnings of a market pullback from Wall Street executives on Tuesday had prompted a sharp sell-off in markets driven by AI-linked stocks.

Apple fell 0.3%, Microsoft was down 1.6% and Nvidia lost 1.2%. The information technology sector fell 1.2%.

DoorDash slumped 16% to the bottom of the S&P 500 after the delivery firm reported third-quarter profit below Wall Street expectations on rising expenses. It weighed on the consumer discretionary sector, which fell 1.3%.

At 10:10 a.m. ET, the Dow Jones Industrial Average fell 266.67 points, or 0.56%, to 47,044.33, the S&P 500 lost 37.16 points, or 0.55%, to 6,759.13 and the Nasdaq Composite lost 214.51 points, or 0.91%, to 23,285.29.

Meanwhile, the longest U.S. government shutdown in history has led to investors and the Federal Reserve flying blind ahead of the next rate decision and reliant on mixed private sector indicators.

Global outplacement company Challenger, Gray & Christmas said on Thursday layoffs announced by U.S. employers surged in October, marking the highest level for the month in 22 years, while data from Revelio Labs showed the economy shed jobs last month.

The data was in contrast to Wednesday's strong ADP report, spurring uncertainty over the health of the U.S. labor market.

"We have uncertainty from the Fed decision next month, on where the tariffs are going, with the government shutdown... the markets are a little bit cautious right now," said Dennis Dick, chief strategist at Stock Trader Network.

"It's been an excellent couple of months for the market and a little bit of a corrective phase here is warranted."

The U.S. formalized changes to reciprocal tariff rates with China in a government posting, a day after the Supreme Court raised doubts over the legality of the duties.

Meanwhile, investors assessed a bag of mixed corporate earnings. Datadog topped the S&P 500 with a 19% surge after the cloud security firm raised its annual profit and revenue forecasts.

Moderna gained 3.5% after the vaccine maker posted a smaller-than-expected third-quarter loss.

Cosmetics-maker Elf Beauty forecast annual sales and profit below expectations, sending its shares down 32%.

Qualcomm dipped 1.7% after the chip designer warned of a possible loss of business next year from its key customer, Samsung, but forecast quarterly sales and profit above market expectations.

Chicago Fed President Austan Goolsbee said the lack of official data "accentuates" his caution about cutting interest rates further, which also weighed on market sentiment.

In other moves, DraftKings was up 2.2% after a Bloomberg News report that Disney signed the company as ESPN's new sports-betting partner.

Declining issues outnumbered advancers by a 1.21-to-1 ratio on the NYSE and by a 1.76-to-1 ratio on the Nasdaq.

The S&P 500 posted 15 new 52-week highs and 16 new lows while the Nasdaq Composite recorded 59 new highs and 112 new lows.