Tech shares were on top again Monday as a heavy week of corporate earnings kicked off while pharmaceutical companies offered mixed news on coronavirus vaccines.
The tech-rich Nasdaq Composite Index finished at a record for the fourth straight session, gaining 0.7 percent to close at 13,635.99.
The S&P 500 rose 0.4 percent to end at 3,855.36, also edging to a fresh record. But the bellwether Dow Jones Industrial Average shed 0.1 percent to 30,960.00.
Shares of Apple, Microsoft and Facebook all moved solidly higher ahead of earnings releases later in the week.
The tech sector has been outperforming other industrial groups in recent sessions after a period where equities linked to the Covid-19 economic recovery led the market.
This week's calendar also includes the Federal Reserve's first monetary policy announcement of the year, as well as Senate confirmation hearings for members of President Joe Biden's cabinet.
Biden on Tuesday signed an executive order giving American companies and products priority in contracting with the federal government, as the new administration attempts to spur domestic manufacturing.
In Covid-19 developments, Merck pulled the plug on two vaccine candidates following disappointing clinical results, although it said would still pursue therapeutics to treat the deadly virus.
Meanwhile, Moderna said lab studies showed its vaccine would remain protective against coronavirus variants first identified in the United Kingdom and South Africa.
Shares of Merck edged up 0.2 percent, while Moderna surged 12.2 percent.
GameStop soared 18.1 percent, extending a rally after an activist short-seller who claimed their shares were overvalued ended his campaign, saying investors in the video game merchant had harassed him and his family.
US movie theater chain AMC Entertainment surged 25.9 percent as it announced it had raised $917 million in funding since mid-December, allowing it to fend off bankruptcy for now as Covid-19 batters the film industry.