Published: January 28, 2026
On January 27, 2026, Citrea officially activated its mainnet — marking the first production-grade zero-knowledge (ZK) rollup Layer 2 built directly on Bitcoin. Citrea brings full EVM-compatible smart contract execution to Bitcoin while preserving its core security model, using zkEVM rollups, BitVM-based trust-minimized bridging, and native Bitcoin Layer 1 settlement for data availability and finality.
At launch, Citrea introduced ctUSD — a fiat-backed, dollar-pegged stablecoin issued via M0 infrastructure and MoonPay, fully backed by short-term U.S. Treasuries and cash reserves. ctUSD enables trustless BTC-collateralized lending: users deposit BTC → mint cBTC → borrow ctUSD — all without custodians or cross-chain bridges. Fraud proofs are challengeable directly on Bitcoin mainnet, making this the first truly native Bitcoin DeFi primitive.
With over 40 launch dApps (including DEXs, lending protocols like Morpho, liquidity tools, privacy services, and prediction markets), Citrea positions Bitcoin as an active financial platform beyond a store of value. Backed by $14M Series A funding (Founders Fund, Galaxy Ventures, Maven11 – 2024), Citrea is now live and open for developers and users.
What is Citrea? Bitcoin’s First ZK-Rollup Layer 2 Explained
Citrea is a Layer 2 scaling solution that brings programmable smart contracts to Bitcoin using zero-knowledge rollup technology. Unlike sidechains (Stacks, Rootstock) or federated bridges, Citrea:
- Executes transactions off-chain in batches (execution slices)
- Generates succinct zero-knowledge validity proofs with zkEVM
- Posts compressed state roots and proofs to Bitcoin L1 via BitVM (Clementine bridge)
- Uses Bitcoin for final settlement and data availability — no separate consensus layer
This architecture delivers:
- EVM compatibility → Ethereum developers can deploy dApps with minimal changes
- Trust-minimized bridging → BitVM fraud proofs require only one honest verifier
- Native BTC security → inherits Bitcoin’s PoW and decentralization
- Scalability → thousands of TPS with low fees
ctUSD Stablecoin – Native Dollar Liquidity for Bitcoin DeFi
ctUSD is Citrea’s native, dollar-pegged stablecoin, issued by MoonPay and powered by the M0 universal stablecoin platform. It is 100% backed by short-term U.S. Treasuries and cash reserves, with institutional-grade compliance and global accessibility (160+ countries).
Key advantages over USDT/USDC:
- Native Bitcoin integration — enables direct BTC-collateralized lending without bridges
- Trustless borrowing — deposit BTC → mint cBTC → borrow ctUSD; fraud proofs settle on Bitcoin L1
- Unified liquidity — on-chain base asset for trading, yield, and settlement on Citrea
- Regulatory alignment — designed with compliance in mind for U.S. and global markets
Citrea BTC-Collateralized Lending – How It Works
Citrea introduces trustless BTC lending without custodians or wrapped tokens:
- User deposits BTC → Clementine bridge mints cBTC (Bitcoin-backed asset)
- cBTC used as collateral in lending protocols (Morpho integration at launch)
- User borrows ctUSD → trades, farms yield, or uses for payments
- ZK proofs ensure security; any fraud is challengeable on Bitcoin mainnet
This removes bridge risks, high fees, and custody dependencies seen in Ethereum-based BTC lending (WBTC, renBTC, tBTC). Citrea unlocks Bitcoin’s idle capital (~$1.2 trillion in dormant BTC) for active DeFi markets.
Citrea vs Other Bitcoin L2s & Ethereum Scaling Solutions
| Feature | Citrea | Stacks | Lightning Network | Ethereum L2s (Arbitrum, Optimism) |
|---|---|---|---|---|
| Base Layer Security | Bitcoin (PoW) | Bitcoin (via PoX) | Bitcoin (payment channels) | Ethereum (PoS) |
| Settlement & DA | Bitcoin L1 (BitVM + ZK proofs) | Bitcoin L1 (PoX) | Bitcoin L1 (on-chain enforcement) | Ethereum L1 |
| Trust Model | Trust-minimized (1 honest verifier) | Partial trust (stacked BTC) | Trustless for payments | Honest majority |
| Smart Contracts | zkEVM (EVM-compatible) | Clarity language | Limited scripting | EVM |
| Native Stablecoin | ctUSD (fiat-backed) | No native stablecoin | No | USDC, USDT, etc. |
| Primary Use Case | BTC-collateralized DeFi & HFT | DeFi & NFTs on Bitcoin | Payments & micropayments | General-purpose scaling |
Citrea uniquely combines Bitcoin security with Ethereum developer familiarity and native stablecoin liquidity — a powerful combination for Bitcoin-native finance.
How to Get Started with Citrea & ctUSD
- Bridge BTC — Use Clementine bridge to mint cBTC (trust-minimized peg to Bitcoin)
- Mint ctUSD — Deposit cBTC as collateral → borrow ctUSD on Morpho or other protocols
- Trade & Earn — Use Valiant DEX, JuiceSwap, Fibrous, or other launch dApps for liquidity and yield
- Monitor Dashboard — Real-time TVL, staking APY, bridge volume, and ₿app activity on Citrea dashboard
Tapbit offers early liquidity for related assets (BTC/USDT, WBTC/USDT, stablecoin pairs) with 0% maker fees and deep order books.
Risks & Considerations
- Early mainnet — Adoption and TVL still ramping; liquidity risks on new dApps
- Bitcoin congestion — High fees during peak periods may affect proof posting
- Regulatory risk — ctUSD and Bitcoin-native DeFi face evolving global rules
- ZK proof finality — Optimistic verification includes challenge windows
- Smart contract risk — Audits completed, but no system is 100% safe
Conclusion & 2026 Outlook
Citrea’s mainnet launch on January 27, 2026 and introduction of ctUSD represent a foundational step toward Bitcoin-native DeFi. By combining zkEVM scalability, BitVM trust-minimization, and a fiat-backed stablecoin, Citrea unlocks lending, trading, yield, and structured products directly on Bitcoin — without compromising security or requiring custodians. With strong backing (Founders Fund, Galaxy, Maven11), 40+ launch dApps, and growing ₿apps ecosystem, Citrea is positioned to drive sustainable blockspace demand and activate Bitcoin’s idle capital (~$1.2 trillion in dormant BTC).
Trade BTC, stablecoins & Bitcoin L2 assets on Tapbit:
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Disclaimer: Cryptocurrency trading involves high risk. Prices are volatile. Bitcoin L2 projects carry technical, adoption, and regulatory risks. This article is for informational purposes only and does not constitute investment advice. Always conduct your own research (DYOR) and never invest more than you can afford to lose.
