The S&P 500 rose on Monday, spurred by a rise in technology shares, to start a shortened holiday week.

Wall Street is coming off a mixed week for the major averages. A late-week surge in tech stocks helped lift the S&P 500 and Nasdaq Composite to their third winning week in four, up 0.1% and 0.5%, respectively. The 30-stock Dow, which has outperformed this month, fell 0.7%, snapping a three-week winning streak.

AI stocks enjoyed a resurgence last week after their recent underperformance. Shares of Oracle, a major laggard, jumped after TikTok agreed to sell its U.S. operations to a new joint venture that includes the software giant and private-equity firm Silver Lake. Nvidia also made a comeback.

However, investors are watching to see whether AI stocks can retain their leadership heading into the year-end, especially as investors rotate into cheaper parts of the market amid concerns about lofty tech valuations. There’s also doubt about whether a “Santa Claus rally” will materialize, as the S&P 500 struggles to hold a key technical level.

“My view a couple of weeks ago was an end of year grind,” said Justin Bergner, portfolio manager at Gabelli Funds. “And I think that’s become an end of year churn.”

The New York Stock Exchange will close early on Wednesday at 1 p.m. ET on Christmas Eve and will be closed Thursday for Christmas Day.