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Proof our price data was not changed

Every night after midnight UTC, our server takes a fingerprint of that day’s raw price files for tokenized stocks, plus the rules we wrote down before any results, and stamps the fingerprints into the Bitcoin blockchain through OpenTimestamps, a free public service. After that, nobody, including us, can change a file without its fingerprint giving it away, and nobody can backdate a copy.

22 days of price data stamped, from Tue 22 Sep 2026 · 22 confirmed in Bitcoin and checked by us · updated 2026-10-14 07:30 UTC

Check it yourself

  1. Download a day’s proof from the table below. The list it proves comes with our data.
  2. Drop the proof and the list on opentimestamps.org. It shows the Bitcoin block that holds the stamp and the time of that block.
  3. To check a data file against the list, compute its SHA-256 fingerprint: on Windows certutil -hashfile FILE SHA256, on a Mac or Linux shasum -a 256 FILE. It must match the line for that file.

A list names each raw file with its fingerprint and size, so the lists come with the data rather than on this page. The table shows the fingerprint of each list, which is what the proof stamps in Bitcoin.

Every day so far

Day (UTC)In BitcoinDownloadList fingerprintData filesStamped (UTC)
Tue 13 Oct 2026Block 971,325, 14 Oct 00:26proof7eb5e89e832e3009…16 files, 129.8 MB14 Oct 00:15
Mon 12 Oct 2026Block 971,162, 13 Oct 00:26proof8b93a6da4405f386…16 files, 125.6 MB13 Oct 00:15
Sun 11 Oct 2026Block 971,010, 12 Oct 00:20proofb9896eb2d6652498…15 files, 122.4 MB12 Oct 00:15
Sat 10 Oct 2026Block 970,851, 11 Oct 00:27proofcc8862bcae098999…11 files, 112.2 MB11 Oct 00:15
Fri 09 Oct 2026Block 970,698, 10 Oct 00:44proofb1299a29205d47a1…11 files, 98.2 MB10 Oct 00:15
Thu 08 Oct 2026Block 970,553, 09 Oct 00:20proof16e0d7bfa31269b0…10 files, 97.4 MB09 Oct 00:15
Wed 07 Oct 2026Block 970,412, 08 Oct 00:29proof8122c9918edc410c…9 files, 97.0 MB08 Oct 00:15
Tue 06 Oct 2026Block 970,258, 07 Oct 00:16proofc6d567ae59ef2f64…9 files, 65.8 MB07 Oct 00:15
Mon 05 Oct 2026Block 970,103, 06 Oct 00:24proof60e6ac0bf761fd29…7 files, 50.4 MB06 Oct 00:15
Sun 04 Oct 2026Block 969,925, 05 Oct 00:31proofa8ebc2ab42590465…7 files, 57.0 MB05 Oct 00:15
Sat 03 Oct 2026Block 969,783, 04 Oct 00:36proofc99b5ee96bc5508f…6 files, 56.9 MB04 Oct 00:15
Fri 02 Oct 2026Block 969,650, 03 Oct 00:20proof686814aac1490347…6 files, 47.9 MB03 Oct 00:15
Thu 01 Oct 2026Block 969,508, 02 Oct 00:31proofa9b934371d509581…4 files, 19.5 MB02 Oct 00:15
Wed 30 Sep 2026Block 969,373, 01 Oct 00:57proof2120af1673f808bf…2 files, 16.1 MB01 Oct 00:15
Tue 29 Sep 2026Block 969,281, 30 Sep 08:30proofbd3e70269ea0a3e9…2 files, 16.1 MB30 Sep 07:50
Mon 28 Sep 2026Block 969,281, 30 Sep 08:30proof04be342f590407cf…2 files, 17.1 MB30 Sep 07:50
Sun 27 Sep 2026Block 969,281, 30 Sep 08:30proof1abb234fecbac93b…2 files, 15.6 MB30 Sep 07:50
Sat 26 Sep 2026Block 969,281, 30 Sep 08:30proof351b541a1db58141…2 files, 15.8 MB30 Sep 07:50
Fri 25 Sep 2026Block 969,281, 30 Sep 08:30proof3d9805d40ed831bb…2 files, 16.0 MB30 Sep 07:50
Thu 24 Sep 2026Block 969,281, 30 Sep 08:30proof313d5ce7bbb9c0ac…2 files, 15.0 MB30 Sep 07:50
Wed 23 Sep 2026Block 969,281, 30 Sep 08:30prooffe83510164e51ab4…1 file, 14.9 MB30 Sep 07:49
Tue 22 Sep 2026Block 969,281, 30 Sep 08:30proof123e2cd02867cce0…1 file, 5.4 MB30 Sep 07:49

Machine-readable: index.json.

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