The prospect of faster-than-expected monetary tightening has rattled Wall Street, dragging the S&P 500 deeper into bear territory Tuesday and forcing investors to reassess a stock market that doesn’t look cheap even after its dramatic selloff.

It has been an ugly spell in markets, reflecting concerns about how the economy will hold up as the Federal Reserve embarks on its sharpest campaign of interest-rate increases in decades. Investors expect an increase of 0.75 percentage point on Wednesday, which would be the largest since 1994. 

Stocks were narrowly mixed Tuesday, with the Dow Jones Industrial Average dropping 152 points, or 0.5%, and the Nasdaq Composite Index rising 0.2%. The Nasdaq and the S&P 500 are in a bear market, defined as a decline of at least 20% from their highs.

Many investors contend that the worst in markets might soon be over, given the extended declines in many market sectors this year and the generally healthy state of the U.S. economy. They say buying the dip has fallen out of favor during this year’s rout but that negative sentiment is often a precursor to an extended rebound.