Wall Street's main indexes ended lower on Monday, kicking off the final week of the year on a softer note, as heavyweight technology stocks retreated from last week's gains that had pushed the S&P 500 to record highs.

The information technology sector weighed on the S&P 500, as most tech and AI-linked stocks declined. Nvidia slipped 1.2 percent and Palantir Technologies dropped 2.4 percent.

"This is (not) the beginning of the end of the tech dominance, it'll turn out to be a buying opportunity," said Hank Smith, director and head of investment strategy at Haverford Trust.

"A big reason for that is the top tech names, excluding Tesla, do not have challenging valuations given their growth rate, the moat around their business and their financial strength, which is unparalleled."

The S&P 500 lost 0.4 percent to 6,905 and the Nasdaq Composite ⁠lost 0.5 percent to 23,474.

The Dow Jones Industrial Average fell 0.5 percent to 48,461.93.

Tesla fell 3.3 percent after hitting a record high last ‍week, weighing on the consumer discretionary sector.

Materials slipped, with precious-metal miners sliding as silver dropped sharply after topping US$80 per ounce for the first time, while gold also fell after back-to-back record highs last week.

Conversely, energy stocks gained almost 1 percent, tracking a 2 percent rise in oil prices.

Bank stocks also retreated after a strong rally this year. Citigroup, among major gainers this year due to progress on resolving some regulatory problems, dropped 1.9 percent on Monday.

The stock has gained nearly 68 percent since the start of the year.

Some investors were hoping for a "Santa Claus rally", a seasonal phenomenon where the S&P 500 typically posts gains in the last five trading days of the year and the first two in January, according to Stock Trader's Almanac.

All three indexes were headed for firm monthly gains, with the Dow and S&P 500 on pace for their eighth consecutive month in the green. (Reuters)