S·B·O·R

SBOR fixing of 31 October 2026, 08:30 UTC. SBOR, dollars borrowed against bitcoin (BTC-COLLATERAL-USD): borrow 6.50%, supply 5.88%, across $3.0B on 5 chains. BTC-COLLATERAL-USDC: borrow 6.96%. SBOR Stacks: SBOR-USD: borrow 2.74%, supply 0.88%. SBOR-BTC: borrow 1.50%, supply 1.34%. SBOR-STX: borrow 1.79%, supply 0.85%. Effective annual rates, read from lending contract state. Plain text: latest.txt. Data: latest.json.

2.74%
0.88%

A Reference Rate for Bitcoin-Backed Credit

The SBOR white paper, version 1 · Guy Zaniratto

Credit is priced against reference rates. A dollar loan says "SOFR plus a spread," and anyone can check the first half. Loans against bitcoin are priced venue by venue, each at its own rate, so a borrower, a fund or an AI agent cannot tell how an offer compares with the market. This paper proposes a reference rate for bitcoin-backed credit: a daily fixing read directly from lending contract state, one borrow and one supply rate built from every eligible market, weighted by size, with every input shown, posted on-chain where contracts can read it, and never rewritten. It sets out what such a rate must be, how the Standard Bitcoin Offered Rate (SBOR) computes it, the rules learned by running it, and what becomes possible once lenders and borrowers use the same rate.

Read online Download the PDF

Stamped on-chain

The paper itself is not on-chain. Its fingerprint is. The SHA-256 below was posted on each chain listed, and each block's time is the date it was stamped. Any change to the PDF, even one character, gives a different hash. Later versions get their own stamp, and this one stays.

Stamps are posted on publication day.

Check it yourself

Download the PDF and run shasum -a 256 SBOR_White_Paper_v1.pdf. The result must equal the hash above and the hash in every transaction. On Stacks, the contract sbor-whitepaper-v1 holds the hash as a constant anyone can read. On Bitcoin, the OP_RETURN reads "SBOR WP1 " followed by the hash. An OpenTimestamps proof anchors the same hash in Bitcoin a second way. The full record is in whitepaper-stamps.json.

/api/v1/latest.json     current fixing, with constituents
/api/v1/history.json    daily series since the index began
/api/v1/backfill.json   reconstructed context, not the record
/api/v1/inversions.json cross venue spread, every three hours
/latest.txt             plain text, one line per currency
/weekly.txt             weekly report, plain text
/llms.txt               method and integration policy
curl -s https://sbor.xyz/api/v1/latest.json \
  | jq '.indices["SBOR-USD"] | {borrow, supply}'

{
  "borrow": 2.74,
  "supply": 0.88
}

npx -y sbor-mcp

https://mcp.sbor.xyz/mcp