Polymarket Up/Down market lookup
Paste a slug like btc-updown-5m-1780949100 and get that market’s window, reference prices, outcome and volume, including markets whose order books Polymarket no longer serves.
Reading the slug
Every Polymarket crypto Up/Down market has a slug in a fixed, predictable shape. Once you can read it you can construct one for any window rather than searching for it.
btc-updown-5m-1780949100
│ │ │ └── Unix timestamp: when the window OPENS, in UTC
│ │ └────── Timeframe: 5m | 15m | 1h | 4h | 24h
│ └───────────── Always "updown"
└───────────────── Coin: btc | eth | solThe trap: the API’s startDate field is when the market object was created, not when trading opens — often a day or more earlier. The slug timestamp is the real window start, and endDate is that plus the timeframe.
What Polymarket keeps
Once a market resolves, Polymarket keeps the market record and a thin price series, and drops the order book. Asking for a settled market’s book returns 404. Its price history comes back at about one point a minute, and only when you pass an explicit start and end:
curl -s "https://clob.polymarket.com/book?token_id=$TOK"
# {"error":"No orderbook exists for the requested token id"} 404
curl -s "https://clob.polymarket.com/prices-history?market=$TOK&startTs=$START&endTs=$END&fidelity=1"
# about 6 points for a 5-minute market
curl -s "https://clob.polymarket.com/prices-history?market=$TOK&interval=max"
# {"history":[]} for older marketsThe lookup above works because these markets were recorded while they ran. More on the mechanics in Up/Down markets explained, and the aggregate resolution statistics are on the market data pages.
Frequently asked questions
- How do I look up a Polymarket btc-updown-5m market?
- Paste the slug — for example btc-updown-5m-1780949100 — into the lookup above. You get the trading window, the reference price at open and close, which side resolved, and the final volume. A full Polymarket event URL works too; the slug is extracted from it. Omitting the trailing timestamp returns the most recent market in that series.
- What does the number at the end of a Polymarket Up/Down slug mean?
- It is the Unix timestamp of the moment the trading window opens, in UTC. In btc-updown-5m-1780949100 the market opens at that timestamp and closes 5 minutes later. Note that this is not the same as the API's startDate field, which records when the market object was created and can be a day or more earlier.
- Why can't I find an older Polymarket market?
- Two reasons. Polymarket returns 404 for a resolved market's order book and keeps only about one point a minute of price history. PolyTest keeps a rolling 31-day archive, so a market that resolved more than 31 days ago is not here either. At that point the order book no longer exists anywhere we know of.
- Can I get the order book for a specific Polymarket market?
- Yes, through the PolyTest API, for any market inside the 31-day window. Each market has point-in-time snapshots with 8 levels of depth on both sides at sub-second resolution, which is what you need to simulate realistic fills. Polymarket's own API cannot provide this for a resolved market.