MLB World Series Champion 2026

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Active sub-markets

Market context

The 2026 Major League Baseball season culminates in October with a best-of-seven World Series contested between the American and National League champions. A single team's victory in that series determines settlement; the current 14% implied probability reflects the aggregate confidence across all 30 franchises competing for that title. With the settlement window closing on 31 October 2026, traders have roughly two years to monitor roster construction, injury patterns, and front-office moves that shape championship contention.

Historical precedent suggests that preseason probabilities for individual teams in a 30-way market typically cluster between 3–5% for favourites, with the aggregate of all YES positions summing to 100%. The 14% figure indicates either concentration on a specific franchise or a market still establishing depth. Past World Series markets show that early-season trades, free-agent signings, and playoff seeding shifts can shift individual team odds by 2–4 percentage points within months. Teams eliminated from playoff contention automatically resolve to NO, narrowing the field as the season progresses.

Key catalysts include the 2025 off-season trades and signings (concluding in late January), spring training performance reports, and mid-season injury announcements affecting star players. The MLB regular season runs April through late September 2026, with playoffs in October. Traders depositing via Klarna, SEPA transfers, or USDC should note that market depth typically increases sharply once the 2026 season begins and real performance data emerges, improving withdrawal liquidity for those managing positions across the settlement window.

Methodology

We track MLB World Series Champion 2026 on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Deposit UK, which mirrors the Polymarket order book at 0% 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 Deposit UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.