Will the US confirm that aliens exist by 2027?

Platform comparison

Market context

The real-world event driving this market is whether any senior US official—President, Cabinet member, Joint Chief, or federal agency head—will definitively state that extraterrestrial life or technology exists before the end of 2026. A YES share in this context represents a bet that such a confirmation will occur, while a NO share bets it will not. Currently, the crowd-implied probability sits at 0% for YES, reflecting deep scepticism that the government will ever make such a definitive claim.

Historically, US disclosures on this topic have avoided confirmation. The first tranche of UFO files released under the PURSUE system in May 2026 contained over 160 documents but explicitly stated there was no evidence of alien life, with the Pentagon labelling all cases as unresolved [3]. Similarly, a 2024 Pentagon report acknowledged encounters with unidentified phenomena but concluded most were ordinary objects, and the All-domain Anomaly Resolution Office (AARO) found no evidence of extraterrestrial beings or technologies [1][2]. These precedents explain why the market assigns near-zero probability to a definitive confirmation.

Traders should monitor the rolling release schedule of PURSUE files, with the third tranche published in June 2026 and new materials expected every few weeks [4]. Key catalysts include any future statements from President Trump or the Department of War regarding the nature of these files, as well as official responses from AARO or the Pentagon. Recent reporting confirms that while public excitement persists, officials continue to assert that no compelling evidence for extraterrestrial life has been found [2]. Any shift from “unresolved” to “confirmed” would be the critical signal for a YES outcome.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Market UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.