{ "schemaVersion": "vultax-public-research-data-v1", "articleUrl": "https://vultax.com/research/how-to-read-election-odds", "datasets": [ { "title": "What a $10,000 buy paid above the screen price on Polymarket midterm contracts", "columns": [ { "name": "Category", "unit": null }, { "name": "Paid above the screen price, $10,000 buy", "unit": "¢" } ], "rows": [ [ "Democratic House at 86.5¢", 0.5 ], [ "Democratic Senate at 53.5¢", 0.8 ], [ "Turek, IA, at 39.5¢", 10.3 ], [ "Whatley, NC, at 8.5¢", 24.1 ], [ "Colom, MS, at 6.5¢", 28.4 ], [ "Tafoya, MN, at 8.5¢", 35.4 ], [ "Republican, DE, at 4.5¢", 36.7 ], [ "Mizusawa, VA, at 4.5¢", 37.5 ], [ "Wess, AL, at 5.0¢", 48.7 ], [ "Achilles, ID, at 1.1¢", 68.7 ] ], "measurementContext": "Cents per contract above the midpoint, median over 58 order-book readings, 12 and 13 September 2026. Each label gives the price on the screen at the time. Fees excluded.", "sources": [ { "label": "Rhode, P and K Strumpf (2008). Manipulating Political Stock Markets: A Field Experiment and a Century of Observational Data. working paper", "url": "https://users.wfu.edu/strumpks/papers/ManipIHT_June2008(KS).pdf", "note": "The full citation, as the authors give it, is under Method and limits. Field experiment on the Iowa Electronic Markets in 2000, printed page 22. The abstract and conclusion cover the Wall Street and 2004 cases." }, { "label": "Wolfers, J. and Zitzewitz, E. — Interpreting Prediction Market Prices as Probabilities, NBER Working Paper 12200, 2006", "url": "https://www.nber.org/papers/w12200", "note": "When a price equals the average belief of traders, and why it may not." }, { "label": "Zitzewitz, E. — Limits to Arbitrage and Prediction Market Efficiency: the Case of PredictIt, NBER Working Paper 35845, 2026", "url": "https://www.nber.org/papers/w35845", "note": "Table 8, election contracts one week out: favourite-longshot slope 1.369." }, { "label": "Polymarket Help Center — How Are Prices Calculated?", "url": "https://help.polymarket.com/en/articles/13364488-how-are-prices-calculated", "note": "The displayed price is the midpoint of the bid-ask spread unless the spread is over $0.10, when the last traded price is used. Read 20 October 2026." }, { "label": "Vultax Research — Polymarket 2026 midterm scorecard", "url": "https://vultax.com/research/midterm-scorecard-2026", "note": "Frozen manifest, rules, checkpoints and code, published 17 October 2026." }, { "label": "Vultax Research — Polymarket efficiency series and method note", "url": "https://vultax.com/research/efficiency-series", "note": "Favourite-longshot slope, bootstrap ranges and the clock diagnostic, first release 16 October 2026." }, { "label": "Vultax Research — Polymarket vs Kalshi midterm odds, 65 matched contracts", "url": "https://vultax.com/research/polymarket-vs-kalshi-midterms-odds-2026", "note": "Order-book depth readings, 12 and 13 September 2026. Only the Polymarket figures are quoted here." }, { "label": "Vultax Research — 69% of sharp Polymarket price moves happened on under $1,500", "url": "https://vultax.com/market-updates/polymarket-sharp-moves-under-1500-dollars", "note": "1,985 moves of 3 points or more inside 30 minutes, 400 busiest open markets, 18 September to 2 October 2026." }, { "label": "Vultax Research — How Polymarket settles markets", "url": "https://vultax.com/research/how-long-polymarket-takes-to-settle-markets", "note": "110,576 markets that ended between 15 August and 10 September 2026." }, { "label": "Conditional formula proofs", "url": "https://vultax.com/datasets/research-proof-library-2026-10-25/scopes/489554e56497613c0a949fe39140a2fc4e3014d8e4ad189b2bbbca8f4680d047.md", "note": "Conditional formulas only. The proofs cover the conditional mathematical formulas; article-specific measurements and numerical results have not been proved." }, { "label": "Per-article scope records and Lean package", "url": "https://vultax.com/datasets/research-proof-library-2026-10-25/README.md", "note": "Dated per-article scope records, Lean source, frozen permitted public inputs, checker logs and a reproducible ZIP. Covers only the scope stated in each record, not the whole study." } ], "measurement": { "kind": "observed", "temporalCoverage": "2026-09-12T18:51Z/2026-09-13T23:21Z", "population": "10 Polymarket midterm contracts from a study of 65", "methodology": "A buy of Yes walked level by level through Polymarket's displayed asks, average price paid minus the midpoint, median over the readings where it filled; no order was placed. Quoted from the Vultax study of 16 September 2026." }, "id": "short-answer-chart", "kind": "published-chart", "description": "A prediction-market price is what a $1 contract costs, not a vote share. On seven thin midterm contracts in September 2026 a $10,000 buy paid 24 to 69¢ above the screen price, and political long shots won more often than priced. Five checks, and how Vultax will score 13,186 midterm contracts.", "articleUrl": "https://vultax.com/research/how-to-read-election-odds", "sectionUrl": "https://vultax.com/research/how-to-read-election-odds#short-answer", "publishedAt": "2026-10-28", "modifiedAt": "2026-10-28", "version": "34a3b91902fec7ecf76de3398993464090e71a8e6f1d3ebb11d13b2bd8c367d5", "isLive": false, "limitations": "Published research snapshots and calculations; these exports do not contain current quotes or live account data. Observation windows and populations are stated in the source captions and methodology. Missing metadata is unknown, not zero. An explainer built on published Vultax measurements and the cited papers, each with its own window, on Polymarket only. Not a forecast by Vultax and not advice to trade.", "downloads": { "json": "https://vultax.com/research/how-to-read-election-odds/data.json?dataset=short-answer-chart", "csv": "https://vultax.com/research/how-to-read-election-odds/data.csv?dataset=short-answer-chart" } }, { "title": "Two clocks: how far 15 to 35¢ political contracts beat their price", "columns": [ { "name": "Category", "unit": null }, { "name": "Won minus price, 15 to 35¢ contracts", "unit": "pts" } ], "rows": [ [ "A week before the scheduled end", 2.6 ], [ "A week before the actual close", 10 ] ], "measurementContext": "Share resolved Yes minus the average price, in points. Polymarket political contracts with scheduled ends from January 2025 to October 2026, one reading per contract a week before the clock shown.", "sources": [ { "label": "Rhode, P and K Strumpf (2008). Manipulating Political Stock Markets: A Field Experiment and a Century of Observational Data. working paper", "url": "https://users.wfu.edu/strumpks/papers/ManipIHT_June2008(KS).pdf", "note": "The full citation, as the authors give it, is under Method and limits. Field experiment on the Iowa Electronic Markets in 2000, printed page 22. The abstract and conclusion cover the Wall Street and 2004 cases." }, { "label": "Wolfers, J. and Zitzewitz, E. — Interpreting Prediction Market Prices as Probabilities, NBER Working Paper 12200, 2006", "url": "https://www.nber.org/papers/w12200", "note": "When a price equals the average belief of traders, and why it may not." }, { "label": "Zitzewitz, E. — Limits to Arbitrage and Prediction Market Efficiency: the Case of PredictIt, NBER Working Paper 35845, 2026", "url": "https://www.nber.org/papers/w35845", "note": "Table 8, election contracts one week out: favourite-longshot slope 1.369." }, { "label": "Polymarket Help Center — How Are Prices Calculated?", "url": "https://help.polymarket.com/en/articles/13364488-how-are-prices-calculated", "note": "The displayed price is the midpoint of the bid-ask spread unless the spread is over $0.10, when the last traded price is used. Read 20 October 2026." }, { "label": "Vultax Research — Polymarket 2026 midterm scorecard", "url": "https://vultax.com/research/midterm-scorecard-2026", "note": "Frozen manifest, rules, checkpoints and code, published 17 October 2026." }, { "label": "Vultax Research — Polymarket efficiency series and method note", "url": "https://vultax.com/research/efficiency-series", "note": "Favourite-longshot slope, bootstrap ranges and the clock diagnostic, first release 16 October 2026." }, { "label": "Vultax Research — Polymarket vs Kalshi midterm odds, 65 matched contracts", "url": "https://vultax.com/research/polymarket-vs-kalshi-midterms-odds-2026", "note": "Order-book depth readings, 12 and 13 September 2026. Only the Polymarket figures are quoted here." }, { "label": "Vultax Research — 69% of sharp Polymarket price moves happened on under $1,500", "url": "https://vultax.com/market-updates/polymarket-sharp-moves-under-1500-dollars", "note": "1,985 moves of 3 points or more inside 30 minutes, 400 busiest open markets, 18 September to 2 October 2026." }, { "label": "Vultax Research — How Polymarket settles markets", "url": "https://vultax.com/research/how-long-polymarket-takes-to-settle-markets", "note": "110,576 markets that ended between 15 August and 10 September 2026." }, { "label": "Conditional formula proofs", "url": "https://vultax.com/datasets/research-proof-library-2026-10-25/scopes/489554e56497613c0a949fe39140a2fc4e3014d8e4ad189b2bbbca8f4680d047.md", "note": "Conditional formulas only. The proofs cover the conditional mathematical formulas; article-specific measurements and numerical results have not been proved." }, { "label": "Per-article scope records and Lean package", "url": "https://vultax.com/datasets/research-proof-library-2026-10-25/README.md", "note": "Dated per-article scope records, Lean source, frozen permitted public inputs, checker logs and a reproducible ZIP. Covers only the scope stated in each record, not the whole study." } ], "measurement": { "kind": "observed", "temporalCoverage": "2025-01/2026-10", "population": "665 contracts on the scheduled-end clock, 747 on the actual-close clock", "methodology": "Clock diagnostic of the Vultax efficiency series, method note and data download of 16 October 2026: share resolved Yes minus mean price for contracts priced 15 to 35¢." }, "id": "clocks-chart", "kind": "published-chart", "description": "A prediction-market price is what a $1 contract costs, not a vote share. On seven thin midterm contracts in September 2026 a $10,000 buy paid 24 to 69¢ above the screen price, and political long shots won more often than priced. Five checks, and how Vultax will score 13,186 midterm contracts.", "articleUrl": "https://vultax.com/research/how-to-read-election-odds", "sectionUrl": "https://vultax.com/research/how-to-read-election-odds#clocks", "publishedAt": "2026-10-28", "modifiedAt": "2026-10-28", "version": "fb85001e682d80298a121be7ec5f6765a51080e6811987276f5380f503f18a1b", "isLive": false, "limitations": "Published research snapshots and calculations; these exports do not contain current quotes or live account data. Observation windows and populations are stated in the source captions and methodology. Missing metadata is unknown, not zero. An explainer built on published Vultax measurements and the cited papers, each with its own window, on Polymarket only. Not a forecast by Vultax and not advice to trade.", "downloads": { "json": "https://vultax.com/research/how-to-read-election-odds/data.json?dataset=clocks-chart", "csv": "https://vultax.com/research/how-to-read-election-odds/data.csv?dataset=clocks-chart" } } ] }