Gold prices edged lower on Tuesday as the U.S. dollar firmed, while investors hunkered down for Federal Reserve Chair Jerome Powell's speech at Jackson Hole later this week.

Jerome Powell has the ideal platform Friday to deliver a clear signal the Federal Reserve is about to resume cutting interest rates. But the economy isn’t giving him an equally clear signal that now is the time.

The Nasdaq fell as megacaps lost, after having rallied for much of the year. Nvidia fell 3.5%, the biggest drop in nearly four months.

By Howard Schneider WASHINGTON (Reuters) -Fed Chair Jerome Powell used the central bank's annual Wyoming research conference to promise inflation-fighting rigor when it was needed in 2022, then last year he came to the defense of the job market with promises of lower interest rates when the unemployment rate seemed on a steady rise.

Investors are tracking talks aimed at ending the Russia-Ukraine war and awaiting Federal Reserve Chair Jerome Powell's speech at Jackson Hole at the end of the week.