LibraryMarkets2020Design paperCorpus record
The Yield Protocol: On-Chain Lending With Interest Rate Discovery
Yield Space. Allan Niemerg, Dan Robinson and Lev Livnev.
Yield Space is an invariant between a target asset and a zero-coupon token. The price of the zero-coupon token implies a rate, and the curve is built so that rate behaves like a rate rather than like a spot commodity.
A reading of the public document. Not a copy of it, and not a claim about a later network that reused the name.
A fixed-rate lending pitch should say what is in the pool and what happens at maturity if the pool is unbalanced.
The five-minute read
The defect
A constant-product pool quotes a price. It does not quote an interest rate for a loan that matures.
The rule
Yield Space is an invariant between a target asset and a zero-coupon token. The price of the zero-coupon token implies a rate, and the curve is built so that rate behaves like a rate rather than like a spot commodity.
How it is put together
A fyToken, or equivalent, pays one unit at maturity. The pool trades it against the underlying. At maturity the token and the underlying should converge.
Where the claim stops
The paper is the curve, not a promise that a later protocol stayed solvent.
One action, walked through
- A lender buys the discounted token from the pool.
- The discount is the rate.
- As maturity approaches, the invariant is meant to pull the price toward par.
- What token matures into what?
The argument, unpacked
Why it is still on the desk
A fixed-rate lending pitch should say what is in the pool and what happens at maturity if the pool is unbalanced.
After the text
Yield, Element, Sense and others implemented variants. The curve, not the brand, is the citation.
What has to be true
- The paper is the curve, not a promise that a later protocol stayed solvent.
- It does not remove oracle risk if something else liquidates the loan.
- Convergence at maturity is an invariant goal, not a legal claim on a borrower.
What happened after the paper
Yield, Element, Sense and others implemented variants. The curve, not the brand, is the citation.
What to check before you use the idea
- What token matures into what?
- Does the curve pull to par, and under what reserves?
- Who is the borrower if the other side is only a pool?
Terms
- Zero-coupon token
- A claim on one unit of the asset at a stated maturity.
- Implied rate
- The discount of that token to par, over the time left.
The problem the paper names
A constant-product pool quotes a price. It does not quote an interest rate for a loan that matures.
What the design proposes
- A fyToken, or equivalent, pays one unit at maturity.
- The pool trades it against the underlying.
- At maturity the token and the underlying should converge.
How the mechanism is specified
- A lender buys the discounted token from the pool.
- The discount is the rate.
- As maturity approaches, the invariant is meant to pull the price toward par.
What this page does not treat as proven
- The paper is the curve, not a promise that a later protocol stayed solvent.
- It does not remove oracle risk if something else liquidates the loan.
- Convergence at maturity is an invariant goal, not a legal claim on a borrower.
Why a venture studio still reads it
A fixed-rate lending pitch should say what is in the pool and what happens at maturity if the pool is unbalanced.
This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.
Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.