25% — Will the US government be shut down for at least 80 days between Feb 7, 2026 and Dec 31, 2026 Kalshi 22% · Polymarket 40% · 18 contracts · $3K volume · medium confidence Updated 2026-06-08 09:27:45 UTC Cross-venue gap: 18pp (Polymarket higher) Why this matters: This question asks whether the federal government will be non-operational for at least 80 cumulative days between mid-February and year-end 2026. The 26% probability reflects moderate concern about extended shutdown scenarios, well below historical precedent. The current estimate appears driven by divided government dynamics and budget negotiations typically concentrated in September-December. Two factors push probabilities in opposite directions: funding deadline pressures (September 30 and December 15 are critical junctures) increase shutdown risk, while recent precedent suggests even contentious negotiations typically produce resolutions before 80-day thresholds are reached. The single largest catalyst will be September 2026 budget negotiations, which historically determine whether Congress can pass appropriations or faces extended standoffs. Without an extraordinary political rupture or budget impasse that month, shutdowns typically remain brief. Key factors: - Historical US government shutdowns since 1976 have averaged 10-16 days; reaching 80 cumulative days would require multiple extended closures or one unprecedented shutdown - September 30, 2026 and December 15, 2026 are statutory funding deadlines where congressional action is required; outcomes of these negotiations will largely determine shutdown probability - Divided government conditions (if present after 2026 elections) correlate with shutdown risk, but even divided Congresses have typically negotiated resolutions before cumulative 80-day threshold - The 17-percentage-point gap between Kalshi (27%) and Polymarket (10%) suggests disagreement on severity of budget impasse likelihood - Related Kalshi contracts show only 44% probability of 150,000+ federal employee cuts by January 2027, suggesting markets do not price in extreme fiscal confrontation scenarios Contracts: - Will any part of the United States federal government take a stake of above 0% in any legal vehicle that owns, directly or indirectly, OpenAI’s for-profit operating entity?: OpenAI — 44¢ Kalshi $3K (weight 99%) - Will Mitch McConnell step down from the Senate before his term ends? — 21¢ Polymarket $15 (weight 1%) - Another US government shutdown & House Winner 2026?: Shutdown & Republican Party — 19¢ Polymarket $3 (weight 0%) - Another US government shutdown & House Winner 2026?: Shutdown & Democratic Party — 81¢ Polymarket $1 (weight 0%) - Will Matthew Stafford lead Pro Football in Passing Touchdowns for the 2026-2027 Regular Season?: Matthew Stafford — 5¢ Kalshi $0 (weight 0%) - Will the number of distinct government shutdowns (as defined in the GOVTSHUTLENGTH contract, with shutdown status checked at 10:00 AM ET each day) be exactly 2 in 2026?: 2 — 59¢ Kalshi $0 (weight 0%) - Will the number of distinct government shutdowns (as defined in the GOVTSHUTLENGTH contract, with shutdown status checked at 10:00 AM ET each day) be exactly 3 in 2026?: 3 — 19¢ Kalshi $0 (weight 0%) - Will the number of distinct government shutdowns (as defined in the GOVTSHUTLENGTH contract, with shutdown status checked at 10:00 AM ET each day) be exactly 4 in 2026?: 4 — 8¢ Kalshi $0 (weight 0%) - ... and 10 more --- ## Methodology SimpleFunctions aggregates live YES-side prices from Kalshi and Polymarket contracts bound to this question. For binary topics the headline is the liquidity-weighted mid-price (weight = log(1 + 24h volume) × freshness, where freshness is 1.0 if updated <24h, 0.7 if <7d, 0.4 otherwise). For multi-outcome (winner-take-all) topics the headline is the current leader's price — disjoint outcomes are never arithmetically averaged. Snapshots refresh every 5 minutes during market hours. ## SF Signal - SF Index, regime, and 30d Brier calibration are computed separately and surfaced at https://simplefunctions.dev/admin/calibration. - No SimpleFunctions index / regime / calibration signal is bound to this topic yet — the headline above is market-derived only. --- *Last verified: 2026-06-08T09:20:10.886Z* By SimpleFunctions — https://simplefunctions.dev/ Cite as: "25% per prediction markets (SimpleFunctions, June 2026)" Canonical: https://simplefunctions.dev/answer/govtshutlength Full data: https://simplefunctions.dev/api/public/query?q=Will%20the%20US%20government%20be%20shut%20down%20for%20at%20least%2080%20days%20between%20Feb%207%2C%202026%20and%20Dec%2031%2C%202026 Provider: SimpleFunctions — https://simplefunctions.dev