Documentation

Fixed yield for tokenized assets.

Version 0.1 · draft

01 — Overview

Durata turns variable yield into two independent instruments: a Principal Token (PT) that redeems for principal at a defined maturity, and a Yield Token (YT) that receives the yield generated until then. Holders can lock a fixed return, trade future yield on its own, and build a term structure across maturities.

02 — The problem

Yield-bearing assets on-chain expose holders to a floating rate. A Treasury-bill product tracks short-term government yields; a tokenized stock earns lending income only while it is borrowed. Either way the rate moves during the holding period, and there is no clean way to lock a return, to take a standalone position on future yield, or to hedge a rate change. Traditional markets solve this with zero-coupon instruments and maturity curves; Durata ports those building blocks.

03 — Core concepts

PT	The right to receive principal at maturity. Normally trades below par before it; the discount is the fixed return.
YT	The right to all eligible yield until maturity. Value depends on realised yield, expected rates, time left and demand.
Maturity	A market is one asset and one date. At maturity the yield period ends and PT becomes redeemable.
Notation	PT-SGOV-2027-07 — principal claim on the SGOV market maturing July 2027.

04 — Lifecycle

Deposit a supported asset → mint one PT and one YT per unit of principal → use or trade either leg → yield accrues to YT → at maturity, settle and redeem PT for principal. Before maturity, PT and YT recombine into the underlying at any time.

05 — Economics

A PT redeeming at 100, bought at 95, returns 5 gross over the remaining term. YT receives the yield of the whole principal while costing only a fraction of it, so a change in expected yield produces an amplified percentage move — the higher-volatility rate instrument of the pair.

Instrument	Exposure	Typical objective
PT	Discount accretion to par	Lock a fixed return, cut rate uncertainty.
YT	Realised yield to maturity	Express a view that yield beats what the market implies.
PT + YT	Full underlying economics	Reconstruct the original position.

06 — Pricing example

Illustration only. Deposit 100 of principal on a one-year market with an indicative 5% yield. PT might trade at 95 and YT at 5. Held to maturity, the PT buyer gains 5 on 95 — about 5.3% gross. If realised yield beats the level implied by the YT price, YT outperforms; if it falls, YT declines. PT holders still carry issuer, settlement, liquidity and smart-contract risk.

07 — Market design

Each market fixes an asset, a maturity, an adapter, accounting rules, fees and emergency limits. v1 ships minting, redemption and PT trading. PT liquidity matters most because the PT price is the fixed yield to maturity. Once several maturities are liquid, their prices imply an on-chain yield curve other protocols can reference.

08 — Initial assets

Phase 1 — tokenized Treasury bills. T-bill yield is transparent, which makes it the right asset to validate pricing, settlement and accounting. Phase 2 — tokenized stocks, whose lending income can be separated with the same model once the adapter can account for intermittent yield. Admission requires reliable principal accounting, observable yield, sufficient liquidity, compatible access rules and a completed review.

09 — Architecture

Factory	Creates one series per (asset, maturity) and holds the two global parameters.
Adapter	The only component that knows how an underlying expresses yield. Must never overstate it.
Series	Custodies the asset, mints PT/YT, books yield, settles at maturity.
PT / YT	Plain ERC-20 claims. Mintable only by their series; no owner, no pause.

Invariants

• Issued claims stay fully accounted against the underlying held.
• Principal never pays a protocol fee.
• Maturity behaviour is deterministic and publicly triggerable.
• Privileged actions are limited to fee, treasury and market creation.

10 — Fees and governance

The protocol fee starts at 3% of realised yield, capped in code at 10%, and applies to no part of principal. DURA is the proposed governance and incentive token: direct incentives to maturities that need liquidity, vote on parameters within risk limits, and potentially share fees through a lock, where legally and technically permitted. Supply, allocation, emissions, lock model and fee-share eligibility remain open.

11 — Risks

Underlying issuer	The tokenized asset may depend on an issuer or SPE.
Smart contract	Bugs may affect minting, accounting, distribution or redemption. Unaudited today.
Adapter	Yield may be measured or attributed incorrectly.
Liquidity	PT or YT may trade with high slippage, or without an exit.
Rate	YT loses value when future yield falls.
Settlement	Redemption may be delayed by the underlying or the chain.
Governance	Privileged roles may be misused or compromised.
Regulatory	Tokenized securities are restricted in some jurisdictions.

12 — Access

Durata follows the legal and transfer restrictions of each supported underlying. The current brief anticipates rules aligned with Robinhood Chain stock-token restrictions, potentially excluding the United States, United Kingdom, Canada, Switzerland and the United Arab Emirates.

13 — Roadmap

0 · Research	Adapters, settlement, AMM, legal perimeter, token model.
1 · Testnet	One T-bill maturity with caps and simulated liquidity.
2 · Mainnet beta	Mint, redeem and PT trading for the first market, capped.
3 · Multi-maturity	Additional maturities and incentives; the curve becomes usable.