> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What is cirBTC?

> Circle Wrapped Bitcoin (cirBTC) is a tokenized BTC backed 1:1 by native Bitcoin, issued by Circle on Ethereum and Arc.

cirBTC is Circle Wrapped Bitcoin—a tokenized representation of Bitcoin (BTC)
issued by Circle on Ethereum and Arc. Every cirBTC is backed 1:1 by native BTC
held at a regulated entity in the Circle group of companies. The BTC is held for
the exclusive benefit of cirBTC holders and segregated from Circle's corporate
assets.

## Why wrap Bitcoin?

Bitcoin is the most widely held digital asset, yet it cannot natively interact
with smart contracts, meaning it cannot be used for lending, borrowing, or
complex trading without being wrapped. cirBTC solves this by creating a
tokenized version of BTC that operates on smart contract blockchains,
transforming idle Bitcoin into productive capital.

* **1:1 backed by native BTC**—every cirBTC is redeemable for the underlying
  Bitcoin
* **Neutral issuer**—Circle doesn't operate a competing exchange or lending
  protocol

Paired with USDC, cirBTC enables institutional workflows such as posting cirBTC
as collateral to borrow USDC and access capital without selling the underlying
Bitcoin position.