Polymarket + Kalshi Top-of-Book Snapshot History

Historical best-bid and best-ask snapshots across Polymarket and Kalshi, time-aligned with game state. Fixed 33-day Parquet archive.

Full schema & known gaps →· Sold as-is — but if a file is broken or won't open, email [email protected] and we'll send a fixed file or refund you. No hassle.

Inspect the free sample rows and schemas before buying.

Frozen artifact delivery: the product page and shipped documentation state the exact coverage, row counts and known limitations. A purchase delivers the advertised frozen artifact; no future refresh is promised unless the checkout terms explicitly say so.

Independent venue book captures Observed partial coverage

Competition-season mapping and the complete fixture denominator are unverified. This is not a complete-season archive.

The venues have separate capture windows. An aggregate book-observation bound is not recorded; these windows do not establish common coverage or per-market continuity.

Kalshi top-of-book capture:
2026-03-28T19:43:33.398421049+00:00 → 2026-04-30T23:59:58.913637161+00:00
Polymarket top-of-book capture:
2026-03-28T17:36:32.743524075+00:00 → 2026-04-30T19:38:20.115488052+00:00

UTC timestamps retain their recorded precision; dates alone identify UTC days. Capture time does not establish exchange quote freshness or an executable fill.

Scheduled sports event times:
start unknown → end unknown

Scheduled event times are not inferred from capture windows or combo trade dates.

Coverage qualifications
  • No season scope declared in the archive manifest
  • Complete-season fixture denominator has not been verified

Why the capture contract matters

The schema and coverage notes identify this artifact's record types: sampled quotes or depth, trade prints, derived outcomes or analysis, depending on the product. Observation time, exchange event time and artifact vintage are different clocks. Read the documented fields, gaps and joins before deciding whether the file fits your research; a quote observation does not establish a fill.

What's in the dataset

Dated snapshot: 78,097,955 total rows · 2026-03-28 through 2026-04-30

Research uses for this dataset

Cross-venue price discovery

Compare best bid and ask observations across Polymarket and Kalshi on one fixed 33-day window.

Spread analysis

Measure the tradeable top-of-book spread rather than relying on last prices or mids alone.

Game-state research

Use the captured score, period and clock fields where present in the documented schema.

Coverage-aware backtests

Keep the disclosed college-basketball and L2-depth limitations explicit in every result.

See the real rows before you buy

We publish real sample rows — not a marketing mockup. Load them in DuckDB, inspect the schema and coverage contract, then decide.

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