Polymarket lists daily SPX up-or-down contract for August 16
Polymarket launched a daily active contract on August 16 titled SPX Up or Down on August 16, letting traders take positions on whether the S&P 500 will close higher or lower. A similar contract for August 15 used the same up-or-down framing and was described as equity momentum executable on close. The August 16 listing repeats the format with a new daily expiry. Both contracts target intraday equity momentum rather than multi-day directional bets.
Daily equity momentum contracts give Polymarket a product that competes with options market single-day expiries. Traders who would otherwise use zero-day-to-expiration options now have a binary payout product with no strike skew to navigate. For Polymarket, the format tests whether prediction market infrastructure can capture equity flow that usually runs through Cboe and OCC clearing.
The August 15 and August 16 back-to-back listings suggest this is a pilot, not a one-off. If daily SPX contracts attract volume, Kalshi and ForecastEx will face pressure to match the product cadence. The risk is settlement friction: S&P 500 closing prices are verifiable, but any delay in Oracle feeds or dispute resolution kills the intraday trader edge. Polymarket's market makers must price that operational risk into tighter spreads than options incumbents already offer.