Before Powell's speech, the Dow declines, while growth stocks keep the Nasdaq afloat.

Heavyweight growth stocks helped the Nasdaq rise on Wednesday, while the Dow and S&P 500 declined as attention turned to remarks from Federal Reserve Chair Jerome Powell later in the day.

According to Joe Saluzzi, co-manager of trading at Themis Trading in Chatham, New Jersey, "the market is anticipating him (Powell) to say maybe we won't do the 75 bps raise. People listen to the Fed Chair speak, and they're waiting for that small indication."

The benchmark S&P 500 index SPX is poised for its second consecutive month of gains thanks to expectations that the Fed would now raise interest rates in smaller increments and recent data showing a minor cooldown in prices.