Polymarket's historical price data is free: its price-history endpoints return the full price series of any outcome, from the first trade to resolution, at resolutions down to one minute, with no key. On Nimb, every market page shows 30 days of hourly prices, and markets.csv gives a free snapshot of the 1061 outcomes on the map with chances now, 24 hours, 7 days and 30 days ago.
Where can I get Polymarket historical data?
| Source | What it holds | Best for |
|---|---|---|
CLOB /prices-history | Price points per token, full history | Charts and backtests of one market |
Data API /v2/prices-history | Bucketed prices, ranges, point-in-time | Clean daily or hourly series |
Data API /v2/trades | Every matched trade: price, size, side, wallet, time | Volume and flow analysis |
| Gamma API (closed markets) | Final prices, end dates, rules, volumes | Outcomes and calibration studies |
| Polygon blockchain | Every on-chain transfer and settlement | Audits, independent indexing |
| Nimb markets.csv | Snapshot of the map, rebuilt every 6 hours | A quick table without code |
All Polymarket endpoints are documented at docs.polymarket.com; the request formats are in the Polymarket API guide.
How do I download a market's price history?
- Find the market's token ID:
GET https://gamma-api.polymarket.com/markets?slug=<market-slug>and readclobTokenIds(the first is Yes, the second No, matchingoutcomes). - Request the series:
GET https://clob.polymarket.com/prices-history?market=<token>&interval=max&fidelity=60for hourly points, orfidelity=1440for daily. - Each point is
{"t": unix seconds, "p": price}. A price of 0.41 is a 41% chance. Save it as CSV with two columns.
For a fixed window, the Data API takes start and end in Unix seconds and a bucket_seconds width; as_of returns the price at one moment.
What should I watch for in historical prices?
- Carried-forward prices. In quiet hours there are no trades; the series repeats the last price. A flat line is not proof of agreement. Nimb's links between markets use only fresh prices for this reason (moved together, moved opposite).
- Last trade versus midpoint. History is built from trades and quotes; in a thin book one small trade can print a price far from the mid-price.
- Resolution jumps. Near the end a price goes to 0 or 1. Studies of accuracy should use prices well before the deadline.
- Multi-outcome events. Each outcome has its own series; in a neg-risk market they sum to about 100% at each moment, not exactly.
- Changed rules. A market's rules can be clarified during its life. Read the final rules before comparing early and late prices.
How accurate were past prices?
Historical data is what accuracy studies are made of. Nimb ran one on resolved 2026 markets: see Polymarket calibration. For the wider evidence see are prediction markets accurate?
What does Nimb keep?
The map's data holds 30 days of hourly prices, buy and sell volume per hour and trade counts for each outcome on the map, which feed the price charts and money flow. Nimb does not yet keep longer history or markets that left the map, except a short archive page for each with its last prices. Known limitations.
Frequently asked questions
Can I download Polymarket price history as CSV?
Polymarket's API returns JSON; converting it to CSV is two columns, time and price. Nimb's markets.csv is a ready-made snapshot, but it holds four points per outcome, not the full series.
How far back does Polymarket data go?
To the first trade of each market. Polymarket has run markets since 2020, and closed markets stay queryable through the Gamma API with closed=true.
Is minute-level data available?
Yes, fidelity=1 on the CLOB endpoint gives one-minute points, subject to rate limits and to the gaps of quiet markets.
Can I use Polymarket data commercially?
Check Polymarket's terms of use for the data you take. Nimb cites Polymarket as the origin of every number it shows.
Last reviewed 8 November 2026 · Data from Polymarket · Not financial advice · Nimb is not affiliated with Polymarket.