Johnson & Johnson rose 3.6% after the drugmaker forecast 2021 profit above estimates and promised data from its widely watched coronavirus vaccine trial soon.
3M Co, which makes N95 face masks and Post-it notes, added 2.5% after it reported a better-than expected quarterly profit helped by lower costs and higher demand for its healthcare products during the pandemic.
"So far earnings have been really strong and the market is looking forward to some of the big tech names starting to report earnings today," said Ross Mayfield, investment strategy analyst at Baird, in Milwaukee.
Tech heavyweight Microsoft Corp edged 0.7% higher, while Advanced Micro Devices Inc dipped 0.2%. Both the companies are expected to report earnings after markets close.
Ten of the 11 S&P sectors rose in early trading with energy and industrials leading gains.
Few if any changes are expected in the central bank's policy statement at the end of a two-day meeting on Wednesday, with Fed Chair Jerome Powell likely to address inflation in his post-meeting news conference.
With the S&P 500 trading at 22 times the 12-month forward earnings, concerns about stock bubbles on Wall Street are sparking fears of a pullback. Investors are keeping an eye out for forecasts from corporate America to justify these higher valuations.
The International Monetary Fund on Tuesday raised its forecast for global economic growth in 2021, but warned of "exceptional uncertainty" amid risks from new waves of Covid-19 infections and variants.
In focus is progress in stimulus talks, with US Senate Majority Leader Chuck Schumer saying on Monday that Democrats may try to pass much of President Joe Biden's proposed $1.9 trillion coronavirus relief bill using a process that would bypass a Republican filibuster and could pass with a majority vote.
"There is a little optimism that there's a path to compromise on stimulus," Mayfield said.
At 09:53 a.m. ET the Dow Jones Industrial Average rose 94.45 points, or 0.31%, to 31,054.45, the S&P 500 gained 2.68 points, or 0.07%, to 3,858.04, and the Nasdaq Composite gained 0.17 points, or 0.01%, to 13,636.17.
General Electric Co jumped about 8% after the industrial conglomerate offered an upbeat outlook for its business this year and reported a surge in quarterly free cash flow.
Regeneron Pharmaceuticals Inc gained 0.5% after the drugmaker said its antibody cocktail was effective in preventing Covid-19 infection, based on interim results from a late-stage study.
American Express Co fell 2.5% after it posted a 15% drop in quarterly profit, as pandemic-led lockdowns and business restrictions kept the credit card issuer's members from traveling and dining out.
Advancing issues outnumbered decliners for a 1.5-to-1 ratio on the NYSE and a 1.3-to-1 ratio on the Nasdaq.
The S&P 500 posted 22 new 52-week highs and no new low, while the Nasdaq recorded 339 new highs and 11 new lows.