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Resolved Prediction Markets by Platform and Month, 2020–2026
Monthly resolved-market counts for Polymarket, Kalshi and Manifold in each platform's fetched sample — a map of how deep each pull reached, not a true trend.
This table counts resolved markets per platform per month in our fetched sample: 2,074 Polymarket, 59,642 Kalshi, 30,000 Manifold. The three platforms were pulled with different methods and different API limits, so this is a sample of each platform’s history, not a complete archive, and the three counts are not on equal footing with each other.
Sort any column or search the table; download the CSV below the table.
Each Platform's Window Is a Pagination Artifact, Not a Trend
Each platform's window in this sample reflects how its API was paginated, not real market activity. Polymarket's public Gamma API caps the reachable sample at roughly 2,100 closed markets, so its coverage runs 2020-01 to 2024-09, concentrated in 2020-2022; the near-absence of Polymarket rows after that is a pagination limit, not a platform decline. Kalshi's 59,642-market sample runs 2024-05 to 2026-09, but 99.8% of it falls in 2026 alone, because Kalshi's public settled-markets index behaves like a rolling recent window rather than a full archive. Manifold's 30,000-market sample, by contrast, is genuinely continuous month over month from 2024-03 to 2026-09, since it was paginated all the way back rather than capped.
Trading volume is not comparable across platforms either: Polymarket and Kalshi report real U.S. dollars, while Manifold reports "mana," its play-money in-app currency with no cash value — summing or ratio-comparing the volume column across platforms would mix real and fake currency. Kalshi is real money; Manifold is play money. Kalshi settles contracts in U.S. dollars under CFTC oversight; Manifold runs on a fake in-app currency ('mana') with no cash value. The two platforms are shown side by side because they are the only ones with a usable, non-circular price-to-outcome record (see below), not because their numbers are directly comparable — a Manifold bettor risking play money has different incentives than a Kalshi trader risking cash, and that difference is a known, plausible explanation for any gap between the two.
Resolved Markets by Platform and Year, 2020-2026
Monthly counts summed to calendar year, 2020-2026 only. Excludes 3 Polymarket rows (2002-07, 2011-07, 2018-06), each a single market with an end date that predates Polymarket's 2020 founding — almost certainly bad metadata in the source API, not real pre-2020 markets; they remain in the full table below.
Full Monthly Table
| Platform▼ | Month▼ | Resolved Markets▼ | Total Volume▼ |
|---|---|---|---|
| Kalshi | 2024-05 | 8 | 0.00 |
| Kalshi | 2024-10 | 60 | 0.00 |
| Kalshi | 2025-03 | 25 | 0.00 |
| Kalshi | 2025-12 | 1 | 0.00 |
| Kalshi | 2026-07 | 2,147 | 62,181,111.55 |
| Kalshi | 2026-08 | 4,389 | 213,909,917.70 |
| Kalshi | 2026-09 | 53,012 | 233,584,436.88 |
| Manifold | 2024-03 | 159 | 723,033.68 |
| Manifold | 2024-04 | 1,004 | 4,445,650.25 |
| Manifold | 2024-05 | 983 | 4,953,167.02 |
| Manifold | 2024-06 | 770 | 13,981,711.17 |
| Manifold | 2024-07 | 930 | 22,895,577.30 |
| Manifold | 2024-08 | 891 | 39,094,849.50 |
| Manifold | 2024-09 | 891 | 21,068,016.08 |
| Manifold | 2024-10 | 851 | 11,350,932.55 |
| Manifold | 2024-11 | 1,327 | 39,896,302.70 |
| Manifold | 2024-12 | 999 | 14,257,437.80 |
| Manifold | 2025-01 | 1,741 | 28,503,406.42 |
| Manifold | 2025-02 | 914 | 8,003,771.63 |
| Manifold | 2025-03 | 705 | 7,338,622.27 |
| Manifold | 2025-04 | 780 | 13,100,822.08 |
| Manifold | 2025-05 | 740 | 8,419,783.22 |
| Manifold | 2025-06 | 789 | 10,101,175.33 |
| Manifold | 2025-07 | 700 | 9,077,160.96 |
| Manifold | 2025-08 | 647 | 8,730,738.23 |
| Manifold | 2025-09 | 726 | 7,092,953.76 |
| Manifold | 2025-10 | 832 | 17,339,937.25 |
| Manifold | 2025-11 | 734 | 6,992,043.36 |
| Manifold | 2025-12 | 977 | 13,216,071.43 |
| Manifold | 2026-01 | 3,124 | 49,955,955.33 |
| Manifold | 2026-02 | 1,436 | 8,802,660.12 |
| Manifold | 2026-03 | 1,146 | 5,714,641.49 |
| Manifold | 2026-04 | 1,044 | 6,416,624.21 |
| Manifold | 2026-05 | 867 | 10,924,465.64 |
| Manifold | 2026-06 | 1,031 | 11,691,772.04 |
| Manifold | 2026-07 | 1,031 | 6,473,318.58 |
| Manifold | 2026-08 | 763 | 4,515,908.01 |
| Manifold | 2026-09 | 468 | 4,368,402.42 |
| Polymarket | 2002-07 | 1 | 83,244.40 |
| Polymarket | 2011-07 | 1 | 1,288.89 |
| Polymarket | 2018-06 | 1 | 10,595.66 |
| Polymarket | 2020-01 | 1 | 44,204.85 |
| Polymarket | 2020-06 | 1 | 13,586.51 |
| Polymarket | 2020-07 | 1 | 14,626.56 |
| Polymarket | 2020-10 | 1 | 107,601.59 |
| Polymarket | 2020-11 | 9 | 11,973,032.71 |
| Polymarket | 2020-12 | 1 | 113,361.64 |
| Polymarket | 2021-01 | 32 | 13,415,538.40 |
| Polymarket | 2021-02 | 62 | 5,799,038.57 |
| Polymarket | 2021-03 | 36 | 13,536,070.87 |
| Polymarket | 2021-04 | 78 | 19,511,631.14 |
| Polymarket | 2021-05 | 132 | 6,332,624.70 |
| Polymarket | 2021-06 | 201 | 13,117,591.01 |
| Polymarket | 2021-07 | 102 | 4,946,165.73 |
| Polymarket | 2021-08 | 89 | 4,122,388.61 |
| Polymarket | 2021-09 | 99 | 5,359,189.86 |
| Polymarket | 2021-10 | 188 | 11,159,952.53 |
| Polymarket | 2021-11 | 412 | 9,131,561.55 |
| Polymarket | 2021-12 | 354 | 5,183,315.31 |
| Polymarket | 2022-01 | 125 | 14,261,745.59 |
| Polymarket | 2022-02 | 45 | 30,858,055.42 |
| Polymarket | 2022-03 | 28 | 653,707.21 |
| Polymarket | 2022-04 | 10 | 169,508.33 |
| Polymarket | 2022-05 | 18 | 72,090.76 |
| Polymarket | 2022-06 | 20 | 81,292.98 |
| Polymarket | 2022-07 | 4 | 244,853.23 |
| Polymarket | 2022-08 | 4 | 450,771.17 |
| Polymarket | 2022-09 | 1 | 358,119.52 |
| Polymarket | 2022-10 | 1 | 40,479.51 |
| Polymarket | 2022-11 | 1 | 243,541.44 |
| Polymarket | 2022-12 | 6 | 323,258.17 |
| Polymarket | 2023-01 | 2 | 875,273.60 |
| Polymarket | 2024-08 | 4 | 5,964,340.01 |
| Polymarket | 2024-09 | 3 | 7,211,246.46 |
Volume is USD for Polymarket/Kalshi and Manifold's play-money mana for Manifold — not comparable across platforms.
Download the full table (CSV) · 74 rows
How the Numbers Were Made
Polymarket rows group all closed=true markets by end date month; Kalshi rows group all settled markets by close-time month, deduped across three fetch batches; Manifold rows group all resolved binary markets by resolution-time month, including CANCEL/MKT resolutions (this table counts markets, not prices, so non-YES/NO resolutions are kept here unlike the calibration pages).
3 Polymarket rows (2002-07, 2011-07, 2018-06) carry a parseable but implausible pre-2020 end date, each for a single market — almost certainly a metadata error in the source API rather than a real market that resolved before Polymarket existed. They are kept in the table (nothing is dropped) but excluded from the chart's yearly aggregation, which starts at 2020.
The category breakdown behind Kalshi's growth is on the settled-markets-by-category-date page: Kalshi's monthly volume here is increasingly driven by its high-frequency "Exotics" product family, not broad-based growth across topics.
Polymarket is not in the calibration and Brier score pages. Its public Gamma API caps the reachable sample at roughly 2,100 closed markets, almost all from 2020–2022, before Polymarket's central-limit order book existed. On those markets the only price field available is the final settlement value (effectively exactly 0 or 1), not a pre-resolution trading price, and the CLOB's price-history endpoint returns no data for them. Using that field as a "forecast" would be circular — it would compare the outcome to itself — so Polymarket is left out rather than faked.
Sources
- Polymarket Gamma API (/markets)primaryPolymarket · primary · retrieved 2026-09-13 · Public API, no key required. Terms at https://polymarket.com/tos
- Kalshi public API (/markets, /series)primaryKalshi · primary · retrieved 2026-09-13 · Public API, no key required. Terms at https://kalshi.com/terms-of-use
- Manifold public API (/v0/search-markets)primaryManifold Markets · primary · retrieved 2026-09-13 · Public API, no key required. Terms at https://manifold.markets/terms