Question 1

What prediction market data does PMData provide?

Accepted Answer

Tick-by-tick order book snapshots, updates, trades, on-chain fills, and Chainlink prices for Polymarket markets.

Question 2

Does the Order Book L2 dataset include only YES token data?

Accepted Answer

Yes. In our Order Book L2 dataset, we include only the YES token side. Polymarket uses a symmetric order book: no_bid = 1 - yes_ask, and no_buy@no_ask = yes_sell@yes_bid.

Question 3

How often is the data updated?

Accepted Answer

The data is updated once a day.

Question 4

How do I download Polymarket historical data?

Accepted Answer

Create an account, generate an API key, then download Parquet files directly over HTTP from the PMData API. The dashboard and docs include copy-ready curl and Python examples.

Question 5

Can I backtest prediction market strategies with this data?

Accepted Answer

Yes. PMData is designed for research and backtesting workflows, including tick-level order book replay and integration with Python analysis tools.

Question 6

Has the data been processed?

Accepted Answer

No, historical data is the same as provided by real-time Polymarket WebSocket APIs with addition of local timestamps.

Question 7

Where is the data collected?

Accepted Answer

Data is currently collected in AWS eu-west-2 (London, Availability Zone 2). Before July 14, 2026, it was collected in GCP, Madrid.

Frequently asked questions