What is a prediction market?
A prediction market is an exchange where users trade binary (or multi-outcome) event contracts — “Will X happen by date Y?” — that settle to a fixed value (typically $1) if the event resolves true and $0 otherwise. The traded price between $0 and $1 is read as the market-implied probability of the event. Because contracts are fully collateralized and settle to a known value, prediction markets have their own metric vocabulary (contracts traded, open interest in contracts, settlement value) that we normalize into the standard Artemis fields below.Platforms we cover
| Platform | Type | Chain / Venue | Data start | Symbol (artemis_id) |
|---|---|---|---|---|
| Polymarket | On-chain | Polygon | Sep 2020 | polymarket |
| Kalshi | Centralized, CFTC-regulated | US exchange (API) | Jun 2021 | kalshi |
| Limitless | On-chain | Base | Apr 2024 | limitless |
| Myriad | On-chain | Abstract / Base | Feb 2025 | myriadmarket |
| Rain.one | On-chain | — | Sep 2025 | rain_one |
| Opinion | On-chain | — | Oct 2025 | opinion |
| Predict | On-chain | — | Nov 2025 | predict |
| Hyperliquid HIP-4 | On-chain | Hyperliquid | May 2026 | hip4 |
| Rothera | Centralized (EOD feed) | 24×7 event-contract venue | May 21, 2026 | rothera |
Drift (
drift) also operates a prediction-market (“BET”) product, but is tracked primarily as a Solana perpetuals/spot venue, so its prediction-market activity is folded into its protocol metrics rather than broken out here.Coming soon
We’re adding the following prediction-market venues soon:- ForecastEx (Interactive Brokers)
- Nadex (Crypto.com | Derivatives North America)
- DKeX (DraftKings, formerly Railbird)
- FanDuel prediction market
Where the data comes from
We use two ingestion models depending on whether a venue settles on-chain or off-chain:On-chain venues (indexed from the blockchain)
Polymarket, Limitless, Myriad, Rain.one, Opinion, Predict, and Hyperliquid HIP-4 settle on public blockchains. For these we index raw trade/fill events directly from archive nodes and raw block feeds, then aggregate to a daily grain. This is the same event-level pipeline used for DEXes and perps — no reliance on a venue-reported dashboard number.- Polymarket — indexed from Polygon. Every fill is a USDC-denominated on-chain event; the raw trade table (
fact_polymarket_trades) feeds the daily model. Because Polymarket settles via UMA’s optimistic oracle, we also track UMA dispute counts and unique disputers, plus maker rebates paid on Polygon. - Hyperliquid HIP-4 — indexed from Hyperliquid’s raw node feed. Outcome markets are fully collateralized; each binary share settles to $1, so notional volume is measured in shares.
Off-chain / centralized venues (venue data feed)
Kalshi is a CFTC-regulated US exchange whose contracts do not settle on-chain, so we ingest from Kalshi’s official data feed (fact_kalshi_trades), denominated in USD.
Rothera is a 24×7 event-contract venue that launched on 2026-05-21. We ingest Rothera’s end-of-day (EOD) market feed — per-contract volume and open interest snapshotted daily. Because the EOD feed carries no per-trade VWAP, USD figures are valued at the contract settlement price, which makes volume_usd/open_interest_usd an approximation rather than a fill-level tally.
How we calculate each metric
All venues are normalized onto the standard Artemis metric fields so they can be compared side-by-side. Not every venue exposes every metric; the table notes where a field is venue-specific.| Metric | Definition | Methodology | Field name |
|---|---|---|---|
| Spot Volume | Daily trading volume across all event contracts. | For on-chain venues, sum of every fill for the day from indexed trade events (USD notional). For Kalshi, USD volume from the exchange feed. For Rothera, this is a contract count (identical to Contracts Traded), pending the family-wide contracts→USD standardization; USD notional is in volume_usd. For HIP-4, notional in binary shares (each share = $1). | SPOT_VOLUME |
| Open Interest | Value of open, unsettled positions at end of day. | End-of-day snapshot of outstanding contracts. On-chain venues value in USD; Kalshi/Rothera report a contract count, with USD in open_interest_usd (Rothera). | OPEN_INTEREST |
| Contracts Traded | Total number of contracts traded that day. | Count of contracts changing hands, independent of price. Reported for Kalshi and Rothera. | CONTRACTS_TRADED |
| Spot Transactions | Number of trades executed that day. | On-chain: count of trade/fill events. Rothera: number of EOD trade records (trade_count). | SPOT_TXNS |
| Spot DAU | Daily active traders. | Distinct trading addresses (on-chain venues) or distinct accounts (centralized venues) that traded that day. | SPOT_DAU |
| MAU | Monthly active traders. | Distinct trader addresses over the trailing 30 days, computed daily (currently exposed for Polymarket). | MAU |
| Fees | Trading/protocol fees generated that day. | Sum of fees taken by the venue on each fill, in USD. Exposed as FEES (protocol total) and SPOT_FEES (spot leg) depending on venue. | FEES / SPOT_FEES |
| TVL | Collateral locked in the protocol. | On-chain collateral backing open positions (exposed where a venue custodies collateral on-chain, e.g. Polymarket). | TVL |
| Active Markets | Distinct markets with activity that day. | Count of distinct markets/symbols that traded. | ACTIVE_MARKETS |
Category & sub-category breakdowns
For the largest venues we split daily volume and open interest into a cross-venue-comparable taxonomy (Sports, Politics, Economics, Crypto, …) so the same categories line up across platforms:- Polymarket and Kalshi expose
SPOT_VOLUME_SPORTS,SPOT_VOLUME_POLITICS,SPOT_VOLUME_CRYPTO, and..._WITHOUT_SPORTSvariants, plus per-category tables (*_metrics_by_category) and hourly tables (*_metrics_by_hour). - Rothera has no category field in its EOD feed, so category is derived from each contract’s product-code prefix (via an internal mapping) into the same cross-venue taxonomy. Rothera additionally offers a sport-level drilldown (Soccer / Baseball / Tennis / American Football / Macro) that is intentionally not cross-venue-comparable.
Reading volume across venues: on-chain venues and Kalshi report USD-denominated volume. Rothera’s
spot_volume and HIP-4’s spot_volume are contract/share counts — use Rothera’s volume_usd when you need a dollar figure, and treat HIP-4 shares as $1 each. We are standardizing all venues onto USD-denominated spot_volume; until then, check the field notes above before summing across platforms.Accessing the data
Prediction-market metrics are available through every Artemis surface:- Web app — Prediction Markets sector on artemis.ai
- API / Python SDK — see Prediction Markets via the API for
fetch_metricsexamples - Sheets — pull the fields above directly into Google Sheets or Excel
- Snowflake Data Share — daily models live under
RESULTS.EZ_METRICS.ez_<venue>_metrics, with breakdowns underRESULTS.EZ_METRICS_BY_DIMENSION

