license: cc-by-4.0
language:
- en
tags:
- finance
- prediction-markets
- microstructure
- polymarket
- order-book
- adverse-selection
pretty_name: Polymarket Crypto Up/Down Microstructure (5m/15m)
size_categories:
- 1M<n<10M
configs:
- config_name: slots
data_files: parquet/slots.parquet
- config_name: book_snapshots
data_files: parquet/book_snapshots.parquet
- config_name: pm_trades
data_files: parquet/pm_trades.parquet
Format. Three tables are published as parquet (under
parquet/) for the Hub viewer and pandas/polars/datasetsusers — pick a table from the config dropdown above. Thehonest-backtestloader reads thisparquet/directory directly via its parquet adapter (adapters.parquet_pm.load_corpus) for one-command reproduction of the paper's results — see Reproduce the headline result below.
Dataset card — Polymarket crypto up/down microstructure (5m/15m)
Six weeks of real order-book microstructure, trade tape, and oracle-settled resolutions for Polymarket's BTC/ETH/SOL/XRP "Up or Down" binary markets (5-minute and 15-minute slots). Captured live, May 27 → Jun 24 2026.
Built following Datasheets for Datasets (Gebru et al.).
Motivation
Why does retail lose the near-close crypto up/down game even when their signal
"predicts"? The honest answer needs real microstructure: the book you saw, the
trades that actually printed, and the ground-truth outcome — at sub-second
resolution near the close. This dataset is that substrate, released so the
honest-backtest results
are reproducible and so others can study adverse selection on a real venue.
Composition
Three parquet tables; the schema is exactly what the honest_backtest
parquet adapter reads:
| table | one row per | key fields |
|---|---|---|
slots |
market (a single up/down slot) | condition_id, coin, duration, open_ts, close_ts, strike, spot_at_open/close, yes_token_id, no_token_id, resolved_side, fee_rate |
book_snapshots |
top-of-book sample (~30s steady, ~1Hz near close) | ts_ms, secs_to_close, yes/no best bid/ask + sizes, top-5 ladder strings, spot, ds_spot |
pm_trades |
a real trade print | ts_ms, token_id, price, size, taker_buy (1=buy/0=sell) |
condition_id/token_id/slug are Polymarket-public market identifiers; they
map to real, already-closed markets. There is no account, wallet, order, or
trade-of-ours information of any kind (see Anonymization).
Collection process
A single always-on recorder subscribed to Polymarket's CLOB market WebSocket
(book + trades) and an independent spot/oracle feed. book_snapshots sampled
top-of-book on a cadence that tightens to ~1Hz inside the final ~5s of each
slot. pm_trades is the raw public trade tape.
Ground-truth resolution (slots.resolved_side) comes ONLY from Polymarket's
gamma outcomePrices (the authoritative settlement oracle), backfilled by a
15-minute cron — never inferred from spot. A YES token pays $1 iff
resolved_side='Yes'; a NO token pays $1 iff 'No'.
Anonymization
The export whitelists three market-observation tables and a fixed column list.
Everything tied to the operator was excluded by construction: our orders, fills,
positions, round-trips, redemptions, on-chain tx hashes, strategy labels, and
maker/shadow decision logs. The exporter asserts: the output contains exactly
{slots, book_snapshots, pm_trades}, no column name matching
order/tx/wallet/strategy/pnl, and no wallet/tx-hash-shaped string in text fields.
Known caveats (read before modeling)
- Crossed / phantom book (~98% of raw deltas; visible in snapshots too).
Displayed ladders are frequently crossed (yes_ask + no_ask ≠ 1; sums < 1 seen
routinely). The inside market must be anchored on
pm_trades(real executions), not taken at face value from the book. This is the central data- quality fact — a naive "buy at displayed ask" backtest is fiction. - Stale levels rarely removed. Old ladder levels persist; depth grows over a slot's life. Filter to recent/large sizes or anchor on the trade tape.
- Window starts May 27 deliberately. An earlier capture era (May 11–23) had
~39% of tight-market
resolved_sidecorrupted by a spot-based inference bug, fixed by moving to gamma-only resolution. That era is excluded here. spotis a Binance-frame consensus, ~10bp off the data_streams oracle Polymarket settles on. For cross-probability features, use spot moves vsspot_at_open, not absolute spot-vs-strike. Grading usesresolved_sideregardless, so outcomes are unaffected.- Order-side data is intentionally absent (only the public trade tape is here); the order-rejection / fill-selection asymmetry is studied in the paper via the operator's private ledger, not in this public release.
Recommended uses
Microstructure research; adverse-selection and execution-quality studies;
realistic backtesting with honest-backtest;
calibration of fair-value models for short-horizon binary markets. Not a
source of a profitable trading signal — the accompanying paper shows realizable
edge is ~0 on this venue by construction.
Reproduce the headline result
pip install "honest-backtest[parquet]" # numpy core + pandas/pyarrow for parquet
# fetch the parquet tables from this dataset
huggingface-cli download kinzikdza/polymarket-updown-microstructure \
--repo-type dataset --local-dir pm_data
# run the calibration anchor against the parquet/ directory
python -m honest_backtest.examples.no_overpriced pm_data/parquet
# expect headline edge_real ~ 0 / negative (live anchor was -0.004)
License
CC BY 4.0. Polymarket market identifiers are public; this release adds no proprietary or personal data.