The S&P 500 has set an intraday record high, bolstering the view that the decade-long US bull market has further to run after consumer spending rose in March and inflation data was benign.
The benchmark index on Monday topped its intraday record of 2,940.91 hit on September 21, rising to a session high of 2,949.52.
The S&P 500 is now up more than 17 per cent for the year to date.
Hopes of a resolution of the US-China trade war, upbeat earnings and a dovish Federal Reserve have powered the rally in stocks this year and, even though Monday's gains were small, strategists said new highs encouraged buying.
"It does create pressure to bring more buyers. Today's headline augments the fear of missing out. It's going to make the bears less bearish or more worried they're going to get run over," Jim Paulsen, chief investment strategist at The Leuthold Group in Minneapolis, said.
A Commerce Department report showed US consumer spending increased by the most in more than nine-and-a-half years in March, but a key inflation measure posted its smallest annual gain in 14 months.
Tame inflation supports the Fed's recent decision to suspend further interest rate increases this year.
As trade talks enter their last leg, US negotiators head to China on Tuesday to hammer out details to end the tariff spat between the two countries.
The Dow Jones Industrial Average rose 11.06 points, or 0.04 per cent, to 26,554.39, the S&P 500 gained 3.15 points, or 0.11 per cent, to 2,943.03 and the Nasdaq Composite added 15.46 points, or 0.19 per cent, to 8,161.85.
The Fed starts a two-day meeting on Tuesday, at the end of which a decision on interest rates will be announced.
Another busy week of earnings is expected, with results due from Google parent Alphabet Inc and Apple Inc among other top names.
