By Medha Singh and Bansari Mayur Kamdar

(Reuters) -The S&P 500 and the Dow hit all-time highs on Thursday, extending a record-setting run as a dip in weekly jobless claims allayed fears over the economic damage from a rampant surge in COVID-19 infections in the United States.

The blue-chip Dow was set to rise for a seventh straight session, its longest streak of gains since March.

The Labor Department’s data showed that the number of Americans filing for new unemployment claims slipped to 198,000 in the week leading up to Christmas, from 205,000 a week earlier. Economists polled by Reuters had forecast 208,000 applications for the latest week.

Equities have rallied recently, albeit in some of the thinnest trading volumes that U.S. stock exchanges have seen this year, as growing evidence emerged that the Omicron variant causes less severe illness than the Delta strain.

Aiding sentiment, top U.S. infectious disease adviser Dr. Anthony Fauci said on Wednesday the surge in cases of the Omicron coronavirus variant in the United States is likely to peak by the end of January.

“We’ve had a year to deal with COVID-19 and investors have started to believe that the economy can continue on if this is going to be the current level or the current type of variant we’re going to face,” said Rick Meckler, partner at Cherry Lane Investments New Vernon, New Jersey.

As Wall Street’s main indexes look to exit the year with their sharpest three-year surge since 1999, the attention will shift towards the pace of U.S. interest rate hikes in the face of soaring prices and supply chain logjams.

The S&P 500 is set to end the year 28.8% higher, while the Dow is looking at a climb of 19%. The Nasdaq is up 23% so far in 2021.

At 11:23 a.m. ET, the Dow Jones Industrial Average was up 24.36 points, or 0.07%, at 36,512.99, the S&P 500 was up 7.56 points, or 0.16%, at 4,800.62, and the Nasdaq Composite was up 78.87 points, or 0.50%, at 15,845.09.

Six of the 11 major S&P 500 sector indexes traded higher, led by communication services.

Stock markets are currently in a historically strong period, also called the “Santa Claus Rally” that typically occurs in the last five trading days of the year and the first two of the new year.

Among individual stocks, Biogen Inc slipped 7.4%, giving back gains from the prior session as Samsung BioLogics denied a media report that said the South Korean firm was in talks to buy the U.S. drugmaker.

China’s ride-hailing firm Didi Global reported a decline in third-quarter revenue, as its domestic business took a hit from a regulatory crackdown. Its shares headed for their sharpest monthly decline since its market debut in June, rose 4%.

“One big factor for the market in 2022 is going to be how we begin to resolve our problems with China… in terms of trade, Chinese stocks that are listed here and general economic relations with the country,” Meckler added.

Advancing issues outnumbered decliners by a 2-to-1 ratio on the NYSE and by a about a 2.5-to-1 ratio on the Nasdaq.

The S&P 500 posted 58 new 52-week highs and no new lows, while the Nasdaq recorded 98 new highs and 132 new lows.

(Reporting by Medha Singh and Bansari Mayur Kamdar in Bengaluru; editing by Uttaresh.V)