Wall Street moved lower overnight, after six straight weekly gains, as investors awaited the next catalyst.
Last week Federal Reserve Chair Janet Yellen said US policy makers will proceed cautiously in terms of raising rates, further underpinning a downgrade for rate hike expectations this year. Yellen is due to speak again on Thursday, along with former Fed chairs Ben Bernanke, Alan Greenspan and Paul Volcker.
Even so, Boston Fed President Eric Rosengren warned that "the very slow removal of accommodation reflected in futures market pricing could prove too pessimistic."
"My assessment is that the US economy is continuing to improve despite the headwinds from abroad," Rosengren said in prepared remarks for a speech on Monday.
"If my forecast is right, it may imply more increases in short-term interest rates than are currently priced into futures markets-but, let me emphasise that my outlook still calls for a gradual pace of increases and, as always, the path should depend on incoming economic data," said Rosengren, who is a Federal Open Market Committee voting member this year.