The S&P 500 ended June on a strong note, capping off its best quarter since 2020, but Polymarket traders are betting the benchmark index could start the second half of the year on a weaker footing.
The S&P 500 gained 0.79% to close at 7,499.36 on Tuesday.
However, the July 1 Polymarket contract implies just a 27% probability that the index will open higher on Wednesday.
Why That Number Matters Tuesday marked the end of June, the second quarter and the first half of 2026, with the S&P 500 finishing the first six months of the year up 9.6% and posting a 14.9% gain in the second quarter, its strongest quarterly performance since the second quarter of 2020.
The S&P 500 opened above the 7,600 level only once during June — at 7,605.31 on June 3.
