Stocks are mixed in subdued trading on the last day of 2021

The New York Stock Exchange operates during normal business hours in the Financial District, Wednesday, Oct. 13, 2021, in New York. Stocks are inching higher in early trading Friday, Dec. 31, the final day of what turned out to be another big year on Wall Street. (AP Photo/John Minchillo, File)

Major U.S. stock indexes were mixed in thin trading Friday afternoon, as the market closed out what has turned out to be another banner year for Wall Street.

The S&P 500 was up less than 0.1% as of 3:18 p.m. Eastern, after spending much of the day flipping between small gains and losses. The Dow Jones Industrial Average was up 0.1% and the Nasdaq composite was down 0.3%.

Most of the stocks in the benchmark S&P 500 index rose, with industrial companies, household goods makers and real estate firms among the sectors driving the market higher. Union Pacific rose 1%, Clorox added 1.1% and Duke Realty rose 1.4%.

Those sectors' gains were being kept in check by a slide in technology and communications stocks. Discovery fell 2.7% and PayPal slid 1.2%.

Vaccine makers were among the better performers, with Pfizer up 1.7% and Moderna up 0.8%. Additional governments had approved their vaccines for younger adults as well as boosters this week.

2021 has been a strong year for stock investors. The S&P 500, which hit its latest record high on Wednesday, is heading for a gain of roughly 27% for the year, or 29% including dividends. That’s nearly as much as the index gained in 2019.

It's also been an eventful year. A wave of consumer demand fueled by the reopening of economies pumped up corporate profits more than expected, which helped keep investors in a buying mood. There was also intense interest in so-called “meme stocks," in which large groups of individual investors bought up shares of beaten-down companies like GameStop and AMC Entertainment, causing institutional investors like hedge funds to lose billions.

The Federal Reserve and other central banks also helped prop up the market by keeping interest rates extremely low, which makes borrowing money more affordable for both companies as well as consumers.

There are still plenty of challenges going into 2022. They include rising inflation, global supply chain disruptions and outbreaks of more contagious variants of the COVID-19 virus..

Trading was very slow Friday. Most investors will not pick up trading until next week, or once fourth-quarter earnings reports start being released in early January.

The yield on the 10-year Treasury note held steady at 1.51%. The bond market closed at 2:00 p.m. Eastern, but stock trading will operate on a normal schedule.