Data & attribution
Updated November 1, 2026.
PredictLedger mirrors public market information to resolve the calls users log. This page lists each source, what we take from it, and what we never do. Each exchange is switched on only after we have read its current terms and observed its real public payloads; until then its markets cannot be logged.
| Source | What we use | How | What we never do |
|---|---|---|---|
| Kalshi | Market titles, tickers, prices, close times and resolutions. | Public market-data endpoints of the Kalshi trade API, read-only, roughly hourly. | Hold or accept a Kalshi API key. Read anyone's account or positions. Route orders. |
| Polymarket | Market titles, condition ids, prices, close times and resolutions. | Public Polymarket APIs and public Polygon on-chain records, read-only, roughly hourly. | Connect a wallet. Read a wallet's positions. Route orders. |
Attribution lines
Wherever an exchange's data appears, we show its attribution line:
- "Market data sourced from Kalshi public market data. PredictLedger is not affiliated with or endorsed by Kalshi."
- "Market data sourced from publicly available Polymarket / Polygon on-chain records. PredictLedger is not affiliated with or endorsed by Polymarket."
Every market links back to its public page on the source exchange. We do not republish exchange logos; names are used only to identify the source. We honour an exchange's written request to stop within five business days.
Your logged calls
Positions are entered by you. Public profiles show resolved calls only. Pro users may make a ledger private. You can delete a call or your whole account at any time; deletion removes the records from the site and from backups within 30 days.
Requests
Exchange, rights-holder or data-subject requests: [email protected].