Polymarket Price History vs Order Book Data
Learn when Polymarket outcome prices are enough and when historical bid and ask depth is needed for replay and execution analysis.
Polymarket price history and order book history answer different research questions. Snapshot price fields show how outcome prices and the reference coin price changed over time. Optional order book data adds the bids and asks needed to inspect displayed liquidity and model execution.
What Price History Can Show
The snapshots endpoint returns time-series fields such as price_up, price_down, and coin_price. This is useful for plotting probability movement, aligning outcomes with the underlying crypto price, and testing signals that depend only on those values.
GET /v1/markets/{slug}/snapshots?limit=1000&offset=0What Order Book History Adds
Set include_orderbook=true to request bid and ask depth for each returned snapshot. Depth helps evaluate spread, available size near a price, and possible fills. It is necessary for more realistic execution analysis than a price series alone can provide.
GET /v1/markets/{slug}/snapshots?limit=1000&offset=0&include_orderbook=trueChoose Data for the Question
| Research question | Useful fields |
|---|---|
| How did the market's implied outcome price move? | price_up, price_down, and snapshot time |
| Did outcome prices move with the reference asset? | Outcome prices and coin_price |
| Was there displayed liquidity for a target order? | Bid and ask levels with include_orderbook=true |
| Could a strategy have received a plausible fill? | Historical depth plus an explicit order and slippage model |
A snapshot is a record of book state, not a complete record of every individual trade. Avoid treating mid-price movement as proof that an order could fill at that price.