Polymarket Fed hike odds double to 66% after September CPI surprise
U.S. inflation came in at 3.7% for September, above the 3.6% forecast. Market-implied odds of an October quarter-point rate hike nearly doubled overnight from 22% to 41%. Polymarket now prices a 66% chance of a hike this month. The contract has drawn $37 million in trading volume. The repricing follows a volatile stretch: just days earlier, weak jobs data had collapsed hike odds across prediction markets. Former Fed governor Kevin Warsh is now given a 42% chance of an action that has occurred only once in 36 years.
The whipsaw in Polymarket's Fed pricing burns traders who sized positions around the earlier 20% baseline. Macro desks now face a 46-point swing in hike odds within a single week, first collapsing on jobs data then spiking on CPI. That volatility undermines prediction markets as a steady signal source for futures and options positioning.
Traders who bought hold contracts after the jobs report are now underwater. The $37 million in volume shows real money is at stake, not retail curiosity. For Polymarket, the episode renews questions about whether its crypto-trader-heavy user base magnifies sentiment swings beyond what fundamental data warrants. The October meeting deadline leaves little time for odds to stabilize before settlement.