Resolution criteria on PolyGram: This market will resolve according to the party of the candidate who wins the IL-12 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 4, 2026. A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources.
PolyGram is an on-chain prediction market where you trade YES or NO outcome shares with real USDC on Polygon. For this market, buy YES if you believe the event will happen, or NO if you think it won't. Your maximum loss is your stake — winning shares pay $1.00 each at resolution. Unlike sportsbooks, there is no house edge: prices are set by supply and demand from other traders and reflect the crowd's real-time probability.
Market outcomes
| Republican Party | 94% YES | 7% NO |
| A | — | |
| C | — | |
| E | — | |
| Democratic Party | 5% YES | 95% NO |
| Other | — | |
| B | — | |
| D | — | |
Illinois's 12th congressional district will elect a representative to the U.S. House in the 2026 midterm elections on 4 November. The current order book on Polymarket prices a Democratic victory at 94%, reflecting substantial confidence in the party's hold on this seat. The district, which encompasses parts of central Illinois including portions of Sangamon County, has shifted considerably over recent cycles, making the current implied probability worth examining against historical performance and demographic trends.
The 94% Democratic probability reflects the district's recent electoral history. Democrat Jerry Costello II won the seat in 2022 with approximately 56% of the vote in what was then the 12th district, and Democrats have held this seat continuously since 2013. However, Illinois redistricting following the 2020 census reshaped the district substantially. Comparable districts with similar demographic compositions and recent voting patterns have shown Democratic margins ranging from 52% to 58% in recent cycles, suggesting the current probability may be pricing in a relatively comfortable but not insurmountable advantage.
Key catalysts for traders include candidate announcements, which typically accelerate through 2025 and into early 2026. Costello's decision whether to seek re-election remains significant; any retirement would substantially alter the race dynamics. National economic conditions, inflation trends, and approval ratings for the sitting administration will influence the broader midterm environment. Local redistricting challenges or demographic shifts in the district warrant monitoring through 2026, as do any significant candidate recruitment efforts by either party.
Resolution is handled by the UMA optimistic oracle on Polygon. A proposer submits the outcome, a two-hour dispute window opens, and if no one stakes a counter-claim the payout is final. Contested outcomes escalate to UMA token-holder voting. Payouts clear in USDC to the winning side.
The mechanics for trading "IL-12 House Election Winner" are the same as any other PolyGram political event contract. Each YES share resolves to $1 if the event happens, or $0 if it doesn't. The current price between 0¢ and 100¢ is the market's probability estimate, set live by the order book.
$18K in lifetime turnover and $21K of resting liquidity puts this market in the below the median by volume for politics contracts on PolyGram. Order-book depth is modest — expect a couple of cents of slippage on $1k+ trades.
The market has been open for 3 months — the price has had time to stabilise as new information arrived.
Higher-volume markets tend to have tighter spreads and faster price discovery — meaning the displayed YES/NO percentages are more likely to reflect the true crowd-implied probability rather than a single trader's directional view.
Resolution is handled by the UMA optimistic oracle on Polygon. A proposer submits the outcome, a 2-hour dispute window opens, and if uncontested the payout is final. Contested outcomes escalate to UMA token holders.
This prediction market is scheduled to close on 3 November 2026. After the resolving event occurs, settlement typically clears within 24 hours once the UMA optimistic oracle confirms the outcome. All payouts are in USDC on the Polygon network.
To trade on this prediction market, create a free PolyGram account at polygram.ink, deposit USDC via Polygon, and place a YES or NO order on the outcome you believe in. You can learn more on our how-it-works page. Your maximum loss is limited to your stake — there is no leverage or margin.
When the outcome is determined, winning YES shares pay out $1.00 each in USDC, while losing shares pay $0. Settlement is handled by the UMA optimistic oracle on Polygon — a proposer submits the result, a two-hour dispute window opens, and if uncontested, payouts are distributed automatically. You can withdraw your winnings to any Polygon wallet.
Prediction-market positions can lose 100% of staked capital. Outcomes are uncertain by definition — historical accuracy of crowd-implied probabilities is high in aggregate but not for any single market. PolyGram does not provide investment advice. Trade only with capital you can afford to lose.
Regulatory status varies by jurisdiction. Germany, the United States, and most EU countries treat Polymarket-style event contracts under one of three frameworks: financial derivative, gambling product, or unregulated novel asset. Consult local counsel before trading.
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