Order-Book Archive · from $149

Every order. Both sides. Since before you got here.

Polymarket shows you the order book as it is now. It publishes no order-book history (a price-history endpoint exists; depth history does not) — when a market moves, the evidence is gone. We have been recording the full depth of every book change since January 2026, and the trade tape since December 2025. This page shows exactly what you get.

Historical full-depth Polymarket order books for backtesting, research and trading infrastructure.

Get a free day of data See pricing

Dec 25JanFebMarAprMayJunJul 26

Trade tape (RTDS)every trade ≥ 10 shares, trader identity, ~88 GB

Crypto order booksBTC/ETH/SOL/XRP 15-min windows, ~43 GB

Sports order booksNBA / NHL / NFL game markets, ~3.3 GB

recorded documented gap off-season — gaps are listed per-file in the manifest. We sell what exists, marked honestly.

Known gaps: the trade tape lost ~8 days in March 2026 to a disk incident; sports books are off-season since Jun 15 and resume in autumn.

One full day of NDJSON + schema + loader notebook. No card required.

One of ~a million records per day

This is what a single moment looks like.

2026-07-10, 14:16:00 UTC — sixty seconds into a BTC 15-minute window. Left: the book as a trader saw it. Right: the raw record you receive. The archive holds one of these for every book change of every window.

Ask price	Size (shares)
spread 1c · mid 0.545
Bid price	Size (shares)

{
  "ts": 1783692960930,
  "crypto": "btc",
  "side": "up",
  "window_slug": "btc-updown-15m-1783692900",
  "time_remaining": 840,
  "event_type": "book",
  "bids": [
    {"price": "0.54", "size": "0.65"},
    {"price": "0.53", "size": "584.73"},
    {"price": "0.52", "size": "614.54"},
    ... all levels, every update
  ],
  "asks": [
    {"price": "0.55", "size": "1278.27"},
    {"price": "0.56", "size": "1981.64"},
    ...
  ]
}

NDJSON, hourly files, gzip. Loads with two lines of pandas. Schema docs and a loader snippet ship with every dataset.

Proof of usefulness

Questions only this archive can answer.

43,297

Is the "free arbitrage" real?

We replayed every sub-$1.00 moment across 2,664 windows. Median lifetime: 1 millisecond. Zero lasted a second. One study, question closed — before risking a dollar.

65 s

Where does arbitrage actually live?

The same math on slower markets persists for a median of 65 seconds. Knowing which market types leave time to act is worth more than any signal.

2.44c

Will fees eat your strategy?

Round-trip taker fees at mid-range prices exceed a 2-cent scalp target. Backtest against real books and 2026 fee curves before you build.

Pricing

Launch pricing for early archive users — join before the first public release.early access

Offer	Contents	Price
Dataset slice	one series, one quarter (e.g. crypto books Q1 2026)	$149
Full archive	all order books to date, crypto + sports	$499
Ongoing feed	daily sync + archive updates	$99 / mo
Trade-tape add-on	full RTDS tape with trader identity, Dec 2025 → (trades ≥ 10 shares; smaller prints not recorded)	+$99
Academic	any of the above, verified students & researchers	−50%

License: non-exclusive, single-team internal use, no raw redistribution. Published research from the data: encouraged, with attribution. Comparable: Tardis.dev sells crypto-exchange book history at $300–550/month per exchange — and covers no prediction market.