S&P 500 (SPX) Opens Up or Down on October 20?

About S&P 500 (SPX) Opens Up or Down on October 20?

S&P 500 (SPX) Opens Up or Down on October 20? is a prediction market on Polymarket. Each outcome's price is the market's implied probability, and a correct share pays 1 USDC when the market resolves.

Yes leads at 61%, decimal odds 1.64.

Yes

61% · odds ×1.64

No

39% · odds ×2.56

Closes

20 Oct 2026