Stocks hovered near session highs by late morning Monday ahead of a midday speech from Federal Reserve Chair Janet Yellen.
The S&P 500 was up 0.45%, the Dow Jones Industrial Average added 0.57%, and the Nasdaq rose 0.42%.
Yellen will give a speech to the World Affairs Council of Philadelphia on Monday afternoon. Yellen's insights will be picked apart with a fine-tooth comb for clues as to when the Fed could next hike rates after it first lifted rates in December.
Fed members will next meet on Tuesday, June 14, with an announcement set for the next afternoon. The chances of a rate hike in June dropped to 4% probability, according to the CME Group, after the number of U.S. jobs added to payrolls in May came in well below expectations. Chances of a rate hike in June were higher than 20% at the end of May.
St. Louis Fed President James Bullard noted that while there is a low chance of a June rate hike, July is still very much in play. Speaking in Singapore, Bullard noted that U.S. labor markets are at or around full employment, one of the strongest arguments for another rate hike.
Atlanta Fed President Dennis Lockhart backed up support for July remaining in play, though a June hike was unlikely.
"The combination of the jobs report on Friday and the 'Brexit' consideration justify patience," Lockhart told Bloomberg Television on Monday. The U.K. will vote in a referendum on June 23 to determine whether or not to exit the European Union.