Maine Senate Election Winner

Platform comparison

Market context

The real-world event at stake is the 2026 U.S. Senate election in Maine, where voters will decide whether a Democrat or Republican wins the open seat. In prediction markets, a YES share pays out if the market’s condition is met—here, that a Democrat wins—while a NO share pays if a Republican wins. The market currently implies a 63% chance of a Democratic victory, meaning traders are betting the incumbent Republican Susan Collins faces a tough challenge against Democratic upstart Graham Platner.

Historically, Maine has been a competitive state for Senate races, with ranked-choice voting often narrowing margins and allowing third-party candidates to influence outcomes. In 2024, the state’s presidential result was R+34.1, yet Senate races have frequently flipped or remained close. Platner’s slight lead in recent polls, as reported by UML on June 4, suggests a shifting dynamic that could explain the current probability. If Platner drops out, the market rules state the Democratic option would still resolve to YES if a Democrat wins, adding complexity to how traders interpret the odds.

Traders should watch for candidate announcements, primary results, and polling updates, especially as the general election nears on November 3, 2026. The ranked-choice primary concluded on June 9, with Collins as the sole Republican qualifier and Platner emerging as the progressive-backed Democrat. Recent polling from the New York Times, updated July 6, shows Platner holding a slight lead, a key catalyst for the market’s current stance. Campaign finance data from the FEC will also reveal funding trends that could shift momentum before the settlement window closes.

Sources: 1 · 2 · 3 · 4 · 5

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 Prediction Market UK, 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

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.

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.

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.

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.