Prediction markets

Prediction market leaderboard: open interest, volume, turnover.

Every venue ranks itself on the metric it picks. OCB picks the metrics, then ranks every venue on the same axis: open interest, turnover, resolution honesty, API latency.

Data as of , refreshed every five minutes.

Total open interest

$0

Total volume 24h

$0

Cohort turnover

...

Active markets

0

Cohort median resolution

...

Cohort p50 API latency

...

Every tracked venue, ranked by open interest

0 venues carry at least one live measurement. Sort any column; venues below the $500.0K open-interest floor keep their figures but are not ranked.

20 of 20 venues

#VenueOpen InterestvVolume 24h::Turnover::Volume 30d::Active Markets::Median resolution::p50 API latency::Markets >$1M::
1Polymarket logoPolymarketOn chain........................
2Polymarket US logoPolymarket USOff chain........................
3Kalshi logoKalshiOff chain........................
4Limitless logoLimitlessOn chain........................
5Myriad logoMyriadOn chain........................
6Manifold logoManifoldOff chain........................
7Rain logoRainOn chain........................
8Predict Fun logoPredict FunOn chain........................
9OPINION logoOPINIONOn chain........................
10Sport.fun logoSport.funOn chain........................
11Augur logoAugurOn chain........................
12Levr Bet logoLevr BetOn chain........................
13PredictStreet logoPredictStreetOn chain........................
14Pascal logoPascalOn chain........................
15Overtime logoOvertimeOn chain........................
16Trueo logoTrueoOn chain........................
17Azuro logoAzuroOn chain........................
18PredictIt logoPredictItOff chain........................
19Smarkets logoSmarketsOff chain........................
20MEMetaculusOff chain........................

Questions about this leaderboard

Which prediction market has the most open interest right now?
The leaderboard below ranks every tracked venue by open interest, read from each venue's public API or from the DefiLlama aggregate.
What does turnover mean on this page?
24-hour volume divided by open interest: how many times a venue's book turns over in a day. A low figure means capital parked on long-dated outcomes, a high one means short-dated markets on a thin book.
Where do the open interest and volume numbers come from?
Open interest comes from the venue where the venue publishes a usable figure and from DefiLlama protocol TVL otherwise, and for open interest that is more often DefiLlama: Kalshi publishes it natively, while Polymarket's gamma field is deprecated and reads an order of magnitude low, so Polymarket and Limitless use TVL. Volume is each venue's own where its API gives one, otherwise DefiLlama. Where a venue's own read is a partial view the aggregate wins: unauthenticated, the harness can only sum Kalshi's event catalog and reaches $2.26M against DefiLlama's $424.8M for the same day, so Kalshi's volume is the aggregate's. Every row's tag names its own source.
Why do some venues show no latency or resolution figure?
Those columns come from separate probes (pm-api-latency, pm-resolution-delay, pm-ws-latency) which run against venues with a documented public API. A venue fed through the DefiLlama aggregate carries open interest and volume but no probe columns, and shows a dash rather than a zero.
Can I cite these numbers?
Yes. Every figure is reproducible from public sources, released under CC BY 4.0, and the bench pages expose machine-readable /api/stat endpoints with the same values and timestamp.

Source: pm-cohort-stats harness (volume, OI, active markets, top market, markets >$1M) plus the live PM bench fleet (api latency, resolution delay, ws latency). All gauges scraped from the public OCB Prom, Click a venue row above to open its dedicated product page. Hover the dotted underline on any value to see how it is computed.

How OpenChainBench measures this

Venue rows aggregate the public APIs of each platform, normalized to USD and UTC days. Venues without a public API are read from the DefiLlama protocol and DEX aggregates, which is also how a venue too new to have documented endpoints enters the cohort. Turnover is 24h volume over open interest, computed only where both legs come from the same venue. Resolution delay comes from the pm-resolution-delay bench (anchor: ProposePrice for UMA backed markets). API latency is the 24h p50 of warm, non cached price requests from us-east, eu-west and Singapore.

Two figures on this page disagree with a venue’s own feed, and the disagreement is deliberate. Kalshi’s unauthenticated trades endpoint reported $2.26M of 24h volume against the aggregate’s $424.8M on 2026-09-23: the public slice is a partial view by construction, so the aggregate is published instead. Polymarket’s gamma open interest field is deprecated and reads far below the protocol’s tracked value, so open interest for Polymarket and Limitless is the DefiLlama protocol figure. Both substitutions are marked on the cell.

Data and methodology released under CC BY 4.0. Reuse with attribution to OpenChainBench.