# Wrapped assets: an interface change or a separate backing claim A wrapped asset represents another asset through a token interface or backing arrangement. A simple ETH wrapper holds ETH and issues an ERC-20 balance; a cross-chain representation may depend on a bridge or custodian. The word wrapped does not guarantee a shared redemption mechanism or a one-to-one market price. Evidence: [WETH9 reference implementation](https://raw.githubusercontent.com/Uniswap/v2-periphery/ed24991304291297c3b4a52818d02f46a17aa9a2/contracts/test/WETH9.sol); [Introduction to blockchain bridges](https://ethereum.org/developers/docs/bridges/) Canonical: https://degreesofsatoshi.com/encyclopedia/wrapped-assets/ Published: 2026-10-02 Substantively modified: 2026-10-02 Independently verified by an automated reviewer: 2026-10-02T15:08:18.373Z AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied. ## Key facts - **WETH example:** The reference wrapper credits deposits and returns ETH on withdrawal. ([WETH9 reference implementation](https://raw.githubusercontent.com/Uniswap/v2-periphery/ed24991304291297c3b4a52818d02f46a17aa9a2/contracts/test/WETH9.sol)) - **Interface:** An ERC-20 balance supports a common token API. ([ERC-20: Token Standard](https://eips.ethereum.org/EIPS/eip-20)) - **Receipt wrapper:** wstETH represents stETH through a changing conversion rate. ([wstETH wrapper](https://docs.lido.fi/contracts/wsteth/)) ## A wrapper can adapt an asset to a token interface ETH is Ethereum’s native asset and is not itself an ERC-20 contract balance. The WETH9 reference implementation accepts ETH deposits and credits a token balance. Withdrawing debits that balance and returns ETH under the contract’s rules. Ignoring transaction costs, depositing two ETH in that reference design credits two WETH units. That is a property of this implementation. It does not establish that every token bearing the WETH name uses the same contract or has the same backing. Evidence: [WETH9 reference implementation](https://raw.githubusercontent.com/Uniswap/v2-periphery/ed24991304291297c3b4a52818d02f46a17aa9a2/contracts/test/WETH9.sol); [ERC-20: Token Standard](https://eips.ethereum.org/EIPS/eip-20) ## Another wrapper can change the accounting display wstETH wraps stETH into a non-rebasing token balance. The amount of stETH represented by each wrapper unit changes with the underlying accounting. Unwrapping returns the claim token; it is not the same operation as completing a staking withdrawal into native ETH. An apparently static wallet quantity can therefore represent a changing quantity of the underlying receipt. When calculating a position, identify whether the number shown is wrapper units, underlying claim units or native assets. Evidence: [wstETH wrapper](https://docs.lido.fi/contracts/wsteth/) ## A representation on another chain adds a verification step A bridge may hold an asset on one chain and issue a representation elsewhere. Returning to the original asset requires that bridge’s verification and redemption process. Other arrangements rely on custodians or different mechanisms. Identify the chain and contract, backing location, authorized minting power and exit route. A one-to-one unit convention is not proof that reserves remain available or that a market will trade at that ratio. Ticker equality is insufficient evidence of asset identity. Evidence: [Introduction to blockchain bridges](https://ethereum.org/developers/docs/bridges/) ## Questions ### Is unwrapping always the same as redeeming the original asset? No. Unwrapping a receipt wrapper can return another claim token. Reaching the original asset may still require a staking withdrawal, bridge operation or custodian process. Evidence: [wstETH wrapper](https://docs.lido.fi/contracts/wsteth/); [Introduction to blockchain bridges](https://ethereum.org/developers/docs/bridges/) ## Claims and scope ### wrapped-assets-quick-answer A wrapped asset represents another asset through a token interface or backing arrangement. A simple ETH wrapper holds ETH and issues an ERC-20 balance; a cross-chain representation may depend on a bridge or custodian. The word wrapped does not guarantee a shared redemption mechanism or a one-to-one market price. Scope: {"collection":"defi","dataAsOf":null,"blockHeight":null} ### wrapped-assets-fact-weth-example WETH example: The reference wrapper credits deposits and returns ETH on withdrawal. Scope: {"collection":"defi","dataAsOf":null,"blockHeight":null} ### wrapped-assets-fact-interface Interface: An ERC-20 balance supports a common token API. Scope: {"collection":"defi","dataAsOf":null,"blockHeight":null} ### wrapped-assets-fact-receipt-wrapper Receipt wrapper: wstETH represents stETH through a changing conversion rate. Scope: {"collection":"defi","dataAsOf":null,"blockHeight":null} ## Sources - [WETH9 reference implementation](https://raw.githubusercontent.com/Uniswap/v2-periphery/ed24991304291297c3b4a52818d02f46a17aa9a2/contracts/test/WETH9.sol) — Uniswap repository. ETH deposits mint WETH balances; withdrawal burns balance and returns ETH. Locator: deposit; withdraw; balanceOf. Retrieved: 2026-10-02. - [ERC-20: Token Standard](https://eips.ethereum.org/EIPS/eip-20) — Ethereum Improvement Proposals. The token spending allowance is separate from a website connection. Locator: Methods: approve, allowance, transferFrom. Retrieved: 2026-10-02. - [wstETH wrapper](https://docs.lido.fi/contracts/wsteth/) — Lido contributors. Fixed wrapper balances with changing stETH conversion rates. Locator: What is wrapped stETH (wstETH)?; wrap; unwrap. Retrieved: 2026-10-02. - [Introduction to blockchain bridges](https://ethereum.org/developers/docs/bridges/) — ethereum.org contributors. Lock/mint, burn/mint and liquidity-based transfers have different trust assumptions. Locator: How do bridges work?; Bridge types; Risk with bridges. Retrieved: 2026-10-02. ## Revision history - 2026-10-02: First publication after primary-source research and independent automated verification. - 2026-10-02: Before first publication, independent review checked and revised: sources. Read the pinned WETH9 test/reference implementation deposit/withdraw, ERC-20 methods, wstETH wrap/unwrap and developer bridge models. The reference code is not misrepresented as proof of a particular live deployment. The receipt-wrapper example correctly ends with stETH, leaving ETH redemption separate. The QA does not generalize WETH mechanics, custody or one-to-one market pricing to every wrapped asset. ## Cite this entry Degrees of Satoshi editorial project. “Wrapped assets: an interface change or a separate backing claim.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/wrapped-assets/