For the complete documentation index, see llms.txt. This page is also available as Markdown.

Loan Lifecycle

Bound term loans are coordinated through PSBTs and enforced by Bitcoin Script.

Origination

At origination, the borrower, lender, and Bound sign a single Bitcoin transaction. The transaction coordinates the loan legs together:

  • The borrower locks BTC into escrow.

  • The lender provides bUSD.

  • The borrower receives the agreed bUSD loan amount.

  • Any origination fee is settled as part of the same transaction.

Because origination is atomic, either every transfer settles together or the transaction does not complete.

Escrow

The BTC collateral sits in a 2-of-2 multisig escrow with a timelock. The escrow has two spending paths:

Path
When it applies
Required signer
Result

Repayment path

During the term and grace period

Borrower plus Bound or lender

Borrower repays and receives BTC back

Default path

After the grace period

Lender

Lender claims the BTC collateral

During the term, the borrower must be a signer for the BTC to move. Bound cannot move collateral by itself.

Resolution

There are two ways a loan resolves:

  • Repayment - the borrower repays principal plus interest and receives the escrowed BTC back.

  • Walk-away - the borrower does not repay by the end of the grace period, keeps the borrowed bUSD, and the lender claims the BTC.

The walk-away outcome is what removes price-based liquidation from the loan. The loan state is based on time and repayment, not BTC market price.

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