U.S. stock indexes slipped Wednesday after the Federal Reserve opted not to cut interest rates for the first time since it began trying to help the economy through easier rates in September. The S&P 500 fell 0.

U.S. stock indexes are rallying toward the close of their best week in two months. The S&P 500 rose 1.1% Friday.

Anxiety over a Chinese startup’s threat to American artificial intelligence dominance faded further Wednesday as investors turned their focus to the Federal Reserve’s rate decision due later in the day.