The Dow Jones Industrial Average ticked up 39 points, or 0.11%, to 35,405, the S&P 500 rose 0.22% and the Nasdaq advanced 0.15%.
The Nasdaq and S&P 500 also set all-time intraday highs.
The S&P 500 notched its 51st record close on Wednesday. The tech-heavy Nasdaq on Tuesday had passed 15,000 for the first time.
The yield on the benchmark 10-year Treasury on Wednesday rose to 1.344% as traders looked to the Jackson Hole symposium later in the week for hints on future Federal Reserve policy.
Some Fed officials believe it would be appropriate for the central bank to begin tapering asset purchases this year, while others said they preferred to wait for more solid economic data, especially on employment.
Investors are looking to Fed Chairman Jerome Powell's Friday speech at the symposium for hints to when the Fed might start pulling back on its massive bond-buying program. The Fed has been buying about $120 billion a month of Treasury securities and mortgage bonds to help prop up the economy during the pandemic.
The Jackson Hole retreat was changed to a virtual format because of rising coronavirus cases caused predominantly by the highly contagious delta variant of COVID.
“Moving Jackson Hole back to an entirely virtual format this year is telling us that Fed officials are taking the delta variant seriously,” said LPL Financial fixed-income strategist Lawrence Gillum. “We’ll have to see if that alters the tapering timeline and importantly the market’s expectations for when the Fed will start to increase short-term interest rates.”
Johnson & Johnson (JNJ) - Get Free Report slipped 0.7% on Wednesday after the health-care giant said trial data showed a second "booster" shot of its coronavirus vaccine triggered a sharp increase in binding antibodies.
If the trial data prove successful over a longer, more detailed study, they could pave the way for booster-shot approval from the Food and Drug Administration.
House lawmakers, meanwhile, pushed forward a $3.5 trillion budget proposal Tuesday night and vowed to vote on a separate $1 trillion infrastructure bill no later than Sept. 27. That would set the path for a massive fiscal push over the coming years in the world's biggest economy.
House Speaker Nancy Pelosi has set a goal of passing both measures by Oct. 1.
Shares of GameStop (GME) - Get Free Report fell 5.1% and AMC Entertainment (AMC) - Get Free Report finished 0.7% lower after the stocks, popular on social media forums like Reddit’s WallStreetBets, surged during the previous session.