The S&P 500 fell on Tuesday as investors rotated out of chip stocks and into cyclical sectors, but Polymarket traders are betting the benchmark index will rebound at Wednesday’s open.

The S&P 500 closed down 0.57% at 7,511.35, while the June 17 Polymarket contract implied an 78% probability that the index will open higher on Wednesday.

Why That Number Matters

Investors are closely watching Wednesday’s Federal Open Market Committee meeting, the first under new Fed Chair Kevin Warsh.

Markets broadly expect policymakers to leave interest rates unchanged at 3.5% to 3.75%, but traders will scrutinize the Fed’s economic projections and commentary for clues on the path ...