New Delhi, Sept. 16 -- S&P 500 and Nasdaq edged higher on Wednesday as investors awaited the Federal Reserve's interest rate decision later in the day, while a decline in crude oil prices offered some relief amid ongoing concerns over inflation and the Middle East conflict.

The Fed is scheduled to announce its rate decision at 2 p.m. ET. The outcome is being closely watched by investors as elevated Treasury yields, persistent inflation and escalating tensions in the Middle East continue to weigh on risk appetite.

Market participants will also closely track comments from Fed Chair Kevin Warsh for indications about the central bank's assessment of inflation and the potential direction of interest rates.

According to the CME FedWatch Tool...