Bitcoin prediction-market odds weakened after a September rally. Kalshi’s contract for Bitcoin reaching $100,000 by Dec. 31, 2026 fell to 34 cents, or a 34% implied probability, from 46 cents on Sept. 23, while Polymarket’s separate market for Bitcoin reaching $85,000 during September 2026 fell to 38%, down 40% in 24 hours. Polymarket assigns a similar 34.5% probability to the $100,000 year-end target. The pullback followed Bitcoin’s decline below $83,000 and coincided with weaker risk appetite, higher oil, expectations of an October Federal Reserve rate hike and roughly $500 million in crypto liquidations. Longer-dated Polymarket contracts carry higher probabilities, including 81% for Bitcoin reaching $100,000 by Dec. 31, 2027.