September hike, priced a day and an hour out: 87.5%

Polymarket priced the 16 September 25 bp hike at 87.5% a day and an hour before the statement, a five-outcome Brier score of 0.029. Polymarket called the Federal Reserve's 16 September decision, and with confidence.

- October hike, 25 September: 62.5%
- October checkpoints, fixed in advance: 4
- Traded on the October decision: $13.9M

Observed 2026-09-15 to 2026-09-16, population: Polymarket's five September 2026 FOMC decision contracts.

Study: https://vultax.com/research/fed-september-decision-coin-flip-polymarket-kalshi
Markdown: https://vultax.com/research/fed-september-decision-coin-flip-polymarket-kalshi.md
Data: https://vultax.com/research/fed-september-decision-coin-flip-polymarket-kalshi/data.json
Share card: https://vultax.com/og/article/research/fed-september-decision-coin-flip-polymarket-kalshi
Live screen: https://app.vultax.com/predictions/topic/powell-fomc
Live embed: https://vultax.com/embed/fed

Vultax Research, Polymarket Had the September Fed Hike at 87.5%: Every 2026 FOMC Decision, Scored, 2026-09-25, https://vultax.com/research/fed-september-decision-coin-flip-polymarket-kalshi