Prediction Market data is currently in beta. It is actively being worked on and improved, but may be unreliable. Polymarket data is live, and Kalshi data will be added soon.At least for the time being, this endpoint requires a Growth or Enterprise plan. Learn more.
Example Query
Get last 30 daily bars using countback:Example Response
Example Response (truncated)
Usage Guidelines
Bar data provides time-series OHLC (Open, High, Low, Close) aggregates for prediction events. Each bar represents a specific time period and includes volume metrics, liquidity snapshots, open interest, and trader activity. Key characteristics:- Event ID format: The
eventIdformat varies by platform:- Polymarket:
<eventSlug>:Polymarket:<exchangeAddress>:<networkId>(e.g.,67284:Polymarket:0xc5d563a36ae78145c45a50134d48a1215220f80a:137) - Kalshi:
<eventSlug>:Kalshi(e.g.,KXMVESPORTSMULTIGAMEEXTENDED-S2026350C4EF9BCE:Kalshi)
- Polymarket:
- Time-series format: Each bar has a timestamp (
t) representing the start of the period - OHLC structure: Metrics like
liquidityUsdandopenInterestUsdcontaino,h,l,cvalues - Multiple resolutions: From 1-minute to 1-week intervals
- Volume tracking: Separate buy/sell volumes in both USD and collateral tokens
- Trader metrics: Track unique traders and trade counts per period
Troubleshooting Tips
Why are some bars missing?
Why are some bars missing?
Bars are only created when there’s activity during that time period. Use
removeEmptyBars: false to include zero-activity bars in the response. This is especially important for charting applications that need continuous time series.How do I calculate net volume?
How do I calculate net volume?
Net volume =
buyVolumeUsd - sellVolumeUsd. A positive value indicates more buying pressure, while negative indicates more selling pressure. This can be useful for identifying sentiment shifts.What's the difference between volumeUsd, totalVolumeUsd, and venueVolumeUsd?
What's the difference between volumeUsd, totalVolumeUsd, and venueVolumeUsd?
volumeUsd: Volume during this specific bar periodtotalVolumeUsd: Cumulative all-time volume as of the bar closevenueVolumeUsd: Cumulative volume as reported by the venue (may differ due to timing)
Why do OHLC values seem unusual for liquidity?
Why do OHLC values seem unusual for liquidity?
Unlike price data, liquidity OHLC represents snapshots taken during the period, not transaction values. High values indicate peak liquidity, low values indicate liquidity drops. These can help identify periods of market stress or high activity.
How should I choose the right resolution?
How should I choose the right resolution?
min1,min5,min15: For real-time monitoring and high-frequency analysishour1,hour4: For intraday trends and active market analysisday1,week1: For long-term trends and historical analysis
What does uniqueTraders count?
What does uniqueTraders count?
The number of unique trader addresses that executed at least one trade during the bar period. This metric helps gauge market participation breadth. A high volume with low unique traders may indicate whale activity.
How do I handle the countback parameter?
How do I handle the countback parameter?
countback lets you request a specific number of bars working backwards from the to timestamp. When using countback, the from parameter is still required but effectively ignored. This is useful for “last N periods” queries without calculating timestamps.