Verify our market data: daily receipts, replays and tape checks

By L2WS · 2026-11-15

A market-data vendor asks you to trust its records. We would rather you could check them. Every closed UTC day of the L2WS record goes through three public checks and gets a fingerprint that never changes once the day is final.

1. A full order-book replay

For each symbol we rebuild the order book from the day's depth updates and compare it, again and again, with the reference snapshots taken during the day. The status page shows how many comparisons matched — for a typical day, more than two million checks with a match above 99.99 %.

2. The trade tape against the exchange's own archive

When Binance publishes its daily trade archive, we compare our recorded tape with it trade by trade and publish the number of missing trades per symbol. Gaps are marked in the data, never filled in.

3. A daily quality index

The Q index summarises sequence gaps, rebuild results and latency for the day, per symbol. A low score is published as it is, together with any incident note.

The daily receipt

When a day is sealed, we publish a receipt: a SHA-256 fingerprint computed over the sorted list of the day's streams, their row counts and the hashes of the stored daily files. If a single row of a final day were ever changed, its fingerprint would change too. Save today's receipts — from the status page or receipts.json — and compare them whenever you like.

How to verify a receipt yourself

1. Download /status/receipt/<day>.json today and keep it.
2. Download it again later. For a day marked final, the root must be identical.
3. Stream and row counts in the receipt match what the SQL console reports for that day.

Receipts reveal no data and no storage details — only the fingerprint, counts and the finalisation flag.