Orderbook tick history
Predexon records the complete orderbook of every major prediction market — every placement, update, cancel, and fill, captured tick by tick from our own always-on infrastructure since January 2026. It is the dataset no real-time feed keeps and no exchange lets you download after the fact.
Reconstruct full book depth at any captured timestamp. Backtest queue position, quote aggressiveness, spread dynamics, and fill probability against what the market actually showed — not against a sampled snapshot.
Every new order added to the book, with price, size, and side
Every modification and removal — track how quotes move
Every execution, matched to the resting order it consumed
The complete book at every level, not a top-of-book sample
Millisecond-resolution event time for exact replay
Question, outcome, venue, and resolution joined to every market
# 1. Quote any slice — free, see size and price first
curl "https://api.predexon.com/v2/data/ticks/quote?venue=polymarket\
&market=fed-rate-cut-september&granularity=raw\
&from=2025-01-01&to=2025-06-30" \
-H "x-api-key: <your-api-key>"
# 2. Download as compressed Parquet via signed URL
curl "https://api.predexon.com/v2/data/ticks?quote_id=qt_8f3a…" \
-H "x-api-key: <your-api-key>"Predexon provides downloadable tick-level orderbook history for Polymarket, Kalshi, and Opinion. Quote any slice for free via the API to see its exact size and price, then download it as compressed Parquet through a signed URL. New accounts get $50 in free data credits.
The raw tick stream itself, plus 100ms, 1s, 1m, and 1h aggregations. Raw ticks contain every placement, update, cancel, and fill, so you can aggregate down to any custom resolution — the aggregated tiers are provided for convenience.
Tick capture began in January 2026 and runs continuously across Polymarket, Kalshi, and Opinion, finalized daily around 06:00 UTC. For earlier history, Predexon's REST API covers Polymarket trades and prices back to 2020.
Yes. Because every event is captured — not sampled — you can replay the book to any millisecond timestamp and see full depth exactly as market participants saw it, including levels far from the touch.
By download size: $40/GiB for Polymarket and $80/GiB for Kalshi and Opinion, with a $5 minimum charge. Every slice can be quoted for free before you commit, filters let you pay only for the markets you need, and re-downloads within 24 hours are free.
Compressed Parquet files delivered via signed URLs — columnar, typed, and ready to load into pandas, Polars, DuckDB, ClickHouse, or any OLAP engine without preprocessing.
Tick-level orderbook history, the fastest WebSocket, and blockchain-indexed analytics for every major prediction market — through one clean, predictable API.