Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Kalshi Fees) Pick polygram.ink (preferred broker) |
5% | 95% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Place a position → |
Polymarket (direct) polymarket.com |
5% | 95% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Place a position → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Place a position → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Place a position → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Place a position → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| December 31 | 5% |
| September 30 | 2% |
| April 30 | 0% |
| June 30 | 0% |
| May 31 | 0% |
| March 31 | 0% |
Market context
The event would require an official US statement that extraterrestrial life or technology exists, from the President, Cabinet, Joint Chiefs, or a federal agency, by 31 December 2026. Current pricing at 0% reflects how high the evidential bar is: the market is not asking whether UAPs are real, but whether the government crosses from “unidentified” to an explicit alien confirmation.
The historical record is one-way. NASA’s 2022 review found no evidence supporting extraterrestrial visitation, and the Pentagon’s AARO said in 2024 it had found no verifiable evidence that any UAP represented alien technology or that any reverse-engineering programme of extraterrestrial material existed.[16][14] Earlier hearings and witness claims have generated headlines, but fact checks noted that testimony about “non-human biologics” or recovered materials has not been validated by official confirmation.[3][6] For a programmatic approach, that means a bot should treat most UAP disclosures as noise unless the issuing body uses unambiguous language about extraterrestrial existence, not merely “unresolved”, “unidentified”, or “no evidence”.
Catalysts to watch are scheduled disclosure drops and any change in government language. The White House/defence disclosure portal for UAP records has been live, and the Pentagon has continued releasing batches of files, which can move sentiment without changing the resolution bar.[1][9] The key dependency is wording: official releases may expand the archive, but unless a qualifying authority explicitly states aliens or extraterrestrial technology exist, the market still resolves No. Recent coverage has also highlighted renewed interest in UFO file releases, but that has so far been framed as transparency rather than confirmation.[13][17]
Methodology
This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi Fees, which mirrors the Polymarket order book directly.
Resolution & payout
Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.
Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.
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 Kalshi Fees. 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.
- What does Polymarket cost to trade?
- Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.
- How fast are USDC deposits?
- Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.
Trade Will the US confirm that aliens exist by 2027? on Kalshi Fees
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