U.S. stocks on Wednesday mostly held on to their gains in volatile trade, as Wall Street digested the implications of the Federal Reserve's supersized 50 basis point rate cut and its signal that more easing was ahead.

Investors are waiting to find out how aggressive the Fed will be when it makes its first interest rate cut since 2020.

The rally will likely be too modest to take the S&P 500 Index above 6,000 before next year, with 44% of the 173 respondents to the latest Markets Live Pulse forecasting the benchmark will rise less than 6% from its Wednesday close and 19% expecting it to decline.