What is Wrapped Bitcoin (WBTC)?
Wrapped Bitcoin (WBTC) is an ERC-20 token on Ethereum that is backed one-to-one by actual bitcoin held in custody. It was launched in 2019 by a consortium of BitGo, Kyber Network and Ren to give Bitcoin holders programmable exposure inside the Ethereum ecosystem without selling their BTC.
Every WBTC minted requires an equivalent amount of BTC to be deposited with the custodian. Every WBTC burned releases the same amount of BTC back to the redeemer. A public proof-of-reserves page shows the live ratio of on-chain WBTC supply against custodied BTC balance.
How does WBTC work?
Minting WBTC is handled by a whitelisted set of merchants who bridge between BTC and the Ethereum contract. Retail users buy and sell WBTC on secondary markets - the 1:1 peg is maintained by arbitrage between WBTC's ERC-20 markets and the real BTC market.
The custody model is multi-institution: BTC is held by BitGo, governance actions are signed by the DAO of merchants and custodians, and the contract itself is upgradeable through a multisig. This design prioritises operational robustness over trustlessness - users are counterparty to the custodian, not to a smart-contract bridge alone.