What eight prediction-market venues list, by category

Where the markets are

Two venues hold most of it. Polymarket lists 288,655 of the 438,005 open markets (66%) and Kalshi 112,905 (26%). The other six — Gemini, Manifold, Predict, Limitless, Opinion and Myriad — list 36,445 between them.

A market count mostly measures how finely a venue slices sport. Of Polymarket's open markets, 244,063 (85%) belong to 14,358 sports events, about 17 markets per event, because a single fixture carries a winner market, point spreads, totals and player props. Kalshi's 4,037 sports events average 15 markets each. At the other end, every Myriad event is a single yes-or-no market.

What each venue's volume is spent on

By share of each venue's own 24-hour volume, sports is the largest category on Polymarket, Kalshi, Gemini and Predict. The shares below are fractions of one venue's total, never of a cross-venue sum: the venues count volume in different units, so a sum across them would mean nothing.

On the smaller venues one question can be most of a day's trading. On this date 49% of Opinion's 24-hour volume came from a single question, which companies will be acquired before 2027, and 54% of Limitless's from one daily up-or-down market on a US aerospace and defence fund. Manifold, which runs on play money, is the one venue where sport barely registers: 55% of its volume was in science and technology, led by questions on when the Millennium Prize problems will be solved, and 40% in politics and elections.

Politics and elections

Counting politics and elections together, they took 11.0% of Polymarket's 24-hour volume and 2.2% of Kalshi's on this date. By number of events the picture is different: Kalshi lists 3,460 open election events, second only to sports, because each House, Senate and governor race — and each vote-share or turnout question about it — is an event of its own. Together they carried 1.8% of Kalshi's volume.

What the counts leave out

These are counts of what pdata tracks, which is less than each venue lists. pdata leaves out markets that settle within hours: intraday up-or-down and price-target markets running on 5-minute to 4-hour cycles are dropped when Polymarket, Kalshi, Predict and Limitless data is ingested, because their 24-hour figures cannot be measured accurately without every trade. Daily up-or-down markets stay in. Kalshi's combination bets are absent too, because Kalshi's events endpoint does not return them.

Some venues are sampled rather than copied whole. pdata takes Manifold's binary and multiple-choice markets with at least 45 traders, from its 2,000 most popular; Myriad markets on the BNB Chain and Abstract networks, not its points markets; and Opinion markets on BNB Chain only.

Until 7 October 2026 the intraday filter missed thirteen 15-minute Kalshi series — gold, silver, copper, platinum, palladium, oil, natural gas, three currency pairs and three crypto contracts — because it matched series by name and Kalshi kept adding new ones. The oldest archived contract from these series closed on 11 August 2026. This report leaves them out of every count. They carried about 44 million contracts of 24-hour volume on this date, on top of the Kalshi figure above.

A correction to pdata's own numbers belongs here too. pdata groups the separate Kalshi events for one game — winner, spread, total, props — under a single game event. Until 7 October 2026 its venue totals read volume from that game event, which never carried any, so every grouped game was missing: the Kalshi 24-hour volume on pdata's homepage was about half the figure in this report. Both are fixed.

The resolved archive

When an event has been closed for ten days, pdata stops tracking it live and keeps a final record: its title, categories, close date, venue link, and the result and last price of up to ten of its largest markets. On 7 October 2026 that archive held 450,216 resolved events. Most date from May 2026 on; events that closed between 2 June and 11 August 2026 are missing, because no backup kept them. The whole archive is published as a nightly file at api.pdata.world/bulk.