What Is Wrapped Bitcoin? A Plain Explanation

Wrapped Bitcoin (WBTC) is an ERC-20 token designed to track the price of Bitcoin 1:1, letting BTC’s value move through Ethereum’s smart-contract ecosystem. It exists specifically because Bitcoin and Ethereum are different networks with different capabilities — Bitcoin has no native smart-contract layer, while Ethereum does, which is the whole reason a wrapped version of BTC is useful there in the first place, a distinction covered in more depth in this ethereum vs bitcoin comparison. This page explains what WBTC actually is, how it gets created and redeemed, who holds the Bitcoin behind it, and what it is not.

What wrapped Bitcoin actually is

WBTC is a token that lives on Ethereum, built to the ERC-20 standard like most Ethereum-based tokens, but its price is designed to track Bitcoin’s price directly rather than trade independently. Every WBTC in circulation is backed by real Bitcoin held in reserve, so the token is meant to represent a claim on actual BTC, not a synthetic derivative that merely follows its price.

The reason this exists at all comes down to what each network can do. Bitcoin’s own base layer supports sending and holding value, but it was not built with the kind of general-purpose smart-contract functionality that lets tokens be lent, borrowed against, deposited into liquidity pools, or used as collateral. Ethereum was built for exactly that. Wrapping BTC is the mechanism that lets Bitcoin’s value participate in Ethereum’s decentralized finance (DeFi) ecosystem without Bitcoin’s own base layer needing to change at all.

How minting and redeeming works

Getting BTC turned into WBTC (minting) and turning WBTC back into BTC (redeeming) both run through a small number of defined roles rather than happening automatically on-chain the way a native BTC transfer does.

To mint, a user sends BTC to a merchant, who requests that the custodian mint the equivalent amount of WBTC on Ethereum. The custodian verifies the BTC was actually received, then mints the WBTC and sends it back through the merchant to the user. Redeeming reverses the process: WBTC is burned, and the custodian releases the corresponding BTC. This keeps the WBTC supply backed by real reserves at every point, but it also means minting and redeeming are not instant, permissionless actions the way sending BTC directly is — they depend on the merchant and custodian actually doing their part.

A concrete walkthrough

It helps to see the mint process as a sequence rather than as an abstract description. Say a user wants to convert 1 BTC into WBTC. First, the user sends 1 BTC to a registered merchant, along with a request to mint. The merchant passes the request to the custodian, along with proof that the BTC was actually sent. The custodian verifies that 1 BTC has genuinely arrived in its reserve wallet — not before, not on a promise, only after confirmation — and only then mints 1 WBTC on Ethereum. That new WBTC is sent to the merchant, who forwards it to the user’s Ethereum address. From that point, the user holds an ERC-20 token usable anywhere Ethereum-based DeFi accepts it, while the 1 BTC that funded it sits in the custodian’s reserve, unavailable to be double-counted or used elsewhere. Redemption runs the same sequence in reverse: WBTC is sent to be burned, and the custodian releases the matching BTC once the burn is confirmed. This is a description of the process itself, not a claim about any specific transaction’s timing or fees, which vary by network conditions.

Who the custodian is, and why that matters

The Bitcoin reserves backing WBTC are held by a custodian, BitGo, in multi-signature wallets with geographically distributed keys. As of 2025, BitGo operates as an OCC-chartered National Trust Bank, which puts a layer of regulatory oversight around the custodial role. This is not a criticism of BitGo specifically — it is simply the structural fact that matters most: unlike holding BTC in self-custody, holding WBTC means trusting custodian’s operational security, solvency, and regulatory standing. If the custodian were ever compromised or became insolvent, redemption could be impaired regardless of what WBTC’s market price was doing at the time. The full trade-off, compared against models that don’t rely on a single custodian, is on the custodial vs trustless bridges page.

How big is the wrapped Bitcoin market

WBTC is not a niche experiment. As of mid-2026, roughly 116,000 to 120,000 WBTC are in circulation, representing approximately $7–8 billion in value — one of the largest single contributors to total value locked across DeFi, and a top-20 cryptocurrency by market capitalization in its own right. That scale is itself informative: it means the custodial model backing WBTC has been operating and being redeemed against at real volume for years, not sitting untested. It does not mean the custodial risk described later on this page has gone away — scale reduces the odds that a design flaw has gone unnoticed, but it does not remove the underlying dependency on the custodian continuing to operate correctly.

WBTC in practice: what it’s actually used for

Once BTC is wrapped, its most common uses on Ethereum fall into a small number of categories. It is deposited into lending protocols as collateral to borrow other assets without selling the underlying BTC exposure. It is supplied to liquidity pools alongside another token, letting the pool facilitate trades between them in exchange for a share of trading fees. And it is used directly as collateral in other DeFi positions the same way a stock might be used as collateral for a margin loan. None of these are things Bitcoin’s own base layer supports on its own — they exist specifically because WBTC is an Ethereum-native token that Ethereum’s smart contracts can read, hold, and act on directly.

WBTC vs native BTC, at a glance

	Native Bitcoin	WBTC
Network	Bitcoin	Ethereum (ERC-20)
Backing	Is the asset itself	1:1 claim on BTC held by a custodian
Smart-contract / DeFi access	None natively	Full access to Ethereum DeFi
Getting your BTC back	N/A — already BTC	Redemption (burn WBTC) or a market swap

This is a deliberately short version of the comparison — the full table, with custody, fees, and redemption spelled out row by row, is on the WBTC vs native Bitcoin page.

What wrapped Bitcoin is not

WBTC is not the same thing as holding Bitcoin in self-custody, and it is not risk-free. Its peg to BTC’s price is backed by trust in the custodial process, not by any property of Bitcoin’s own network. It is also not a way to make Bitcoin’s base layer support smart contracts — Bitcoin’s own protocol is unchanged; only a token representing a claim on BTC gains that functionality, on a different network entirely. Anyone treating WBTC as functionally identical to self-custodied BTC is missing the actual trade-off being made. The full breakdown of what that trade-off costs in risk terms is on the WBTC risk profile page.

A pre-use checklist

• Know who the custodian is and what backs the token before holding or using it — for WBTC, that is BitGo.
• Understand that minting and redeeming are not instant or permissionless the way a native BTC transfer is.
• Treat WBTC’s peg as a trust-based mechanism, not a guarantee — it can move away from exactly 1:1 under stress.
• Compare the custodial model to trustless alternatives before assuming custodial is the only option.
• Never treat WBTC as equivalent to Bitcoin self-custody when weighing where to hold value long-term.

Frequently asked questions