The U.S. dollar hovered below a one-week high on Thursday and Asian stock markets were broadly mixed as investors braced for three days of potentially market-moving news from the Federal Reserve's annual symposium in Jackson Hole.

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.