Wall Street to edge down at open; Yellen testimony awaited

By Yashaswini Swamynathan
(Reuters) – U.S. stocks were set to open slightly lower on Wednesday, after a recent spate of record highs, as investors assessed upbeat economic data that strengthened the prospect of an interest rate hike.
Federal Reserve Chair Janet Yellen said on Tuesday, before the U.S. Senate Banking Committee, that delaying a rate hike would be unwise, but did not indicate when the Fed would raise rates.
While she painted a largely upbeat picture of the economy, she also e