Citrea Bitcoin Rollup Debuts Mainnet With ctUSD Stablecoin

Citrea, a Bitcoin-native ZK-rollup backed by Founders Fund and Galaxy Ventures, launched its mainnet on Tuesday, delivering BTC-collateral lending, BTC-structured products, and a new dollar-backed stablecoin, ctUSD. The project, developed by Chainway Labs, positions itself as an on-chain engine that converts idle BTC into core DeFi liquidity and enables closer settlement to Bitcoin’s base layer. In its early days, Citrea projects DeFi activity to reach about $50 million in liquidity as BTC lending, BTC-structured products, and decentralized trading go live from day one, with ctUSD anchoring that activity in a compliant, on-chain fashion.

The launch thrust Citrea into a familiar debate about the allocation of scarce Bitcoin block space: should it be reserved for payments or harnessed to power a broader financial stack? With block rewards trending lower over time, many developers argue that non-payment use cases are essential to sustaining miner revenue. Critics, however, warn that complex DeFi infrastructure built on top of Bitcoin may introduce new risk layers to a network historically prized for censorship resistance and simplicity.

Key takeaways

• Citrea’s mainnet introduces BTC-collateral lending and BTC-structured products on a native rollup, with ctUSD serving as the primary dollar-pegged stablecoin (CRYPTO: CTUSD).
• ctUSD is issued 1:1 with cash and short-term US Treasuries backing and leverages MoonPay’s banking rails, embedding fiat on- and off-ramps directly into the Layer 2 settlement layer.
• The stablecoin is designed to be the single, preferred liquidity anchor for Citrea, aiming to avoid liquidity fragmentation that typically arises from bridged asset variants.
• On the testnet, data-availability usage reached almost 10% of Bitcoin’s monthly bandwidth at one point, signaling meaningful early activity even before full mainnet adoption.
• The launch rekindles the broader industry discussion about the balance between Bitcoin’s block space constraints and the growth of on-chain DeFi ecosystems built atop Bitcoin’s security guarantees.

Tickers mentioned: $BTC, $USDT, $USDC, $CTUSD

Sentiment: Neutral

Market context: The move sits at the intersection of Bitcoin’s evolving role as a settlement layer and the broader DeFi push into alternative layer-2 constructions, aligning with ongoing industry experimentation around scalable, regulated fiat-backed tokens on Bitcoin-adjacent systems.

Why it matters

Citrea’s mainnet marks a noteworthy attempt to redeploy Bitcoin’s scarce block space toward productive financial uses. By tying a Bitcoin-anchored rollup to a regulated, cash-backed stablecoin, the project aims to reduce the liquidity fragmentation that often accompanies cross-chain solutions. ctUSD is issued directly on the Citrea rollup rather than bridged from another chain, which Citrea’s leadership argues reduces exposure to common cross-chain risks and collateral vulnerabilities that can accompany wrapped assets.

Orkun Mahir Kılıç, the co-founder and CEO of Chainway Labs—the team behind Citrea—describes ctUSD as native to the rollup and integrated with MoonPay’s banking rails, including virtual IBANs that enable fiat to be wired in and settled on-chain automatically. This approach is intended to streamline onboarding for users and institutions that require regulated rails for fiat-to-crypto movements, potentially lowering friction for Bitcoin-denominated DeFi interactions. In practical terms, ctUSD’s 1:1 backing in cash and short-dated Treasuries is positioned as a safer alternative to stamped-wrapped tokens that often rely on third-party solvency guarantees.

The design emphasizes security and consolidation. ctUSD’s native issuance on the Citrea chain means the stablecoin inherits the security properties of the Citrea network itself, rather than relying on external bridges that have historically been a hotspot for exploits. Advocates argue this reduces the external risk profile typically associated with cross-chain liquidity but acknowledge that the trade-off is a more centralized sequencing and treasury structure—the so-called “single sequencer” and a private, on-chain treasury with multi-party governance. Critics counter that such trust assumptions could shift systemic risk from on-chain code to off-chain operational controls, raising questions about decentralization and resilience.

On the broader front, the project is framed as an experiment about demand for Bitcoin block space. Bitcoin core developers and industry observers have noted that future miner revenue may increasingly depend on non-payment use cases. The debate is far from settled: if Citrea and similar ventures can demonstrate sustained, productive demand for block space—without undermining Bitcoin’s core reliability—the model could influence how the network balances throughput, fees, and security in a mature DeFi era. A notable point of discussion is whether complex DeFi activity truly complements Bitcoin’s mission or if it creates an overbuilt infrastructure that competes with Bitcoin’s primary function as a trustworthy payments network.

In the broader crypto ecosystem, the move echoes a wave of experimentation where other teams have pursued Bitcoin-focused DeFi applications, including collaborations and cross-ecosystem initiatives. For instance, partnerships that bring Bitcoin DeFi tools to institutions in Japan have highlighted the appetite for regulated, Bitcoin-linked financial services, underscoring a market that is increasingly receptive to institutional-grade rails and compliant stablecoins built around BTC.

Citrea’s early data on testnet activity underscores a meaningful appetite for on-chain Bitcoin usage. In its test phase, Citrea reported that data-availability usage accounted for a notable share of Bitcoin’s bandwidth, suggesting that even pre-launch activity can exert real pressure on block space. If the mainnet proves scalable and capable of sustaining $50 million in DeFi liquidity over the coming weeks, it could set a precedent for how Bitcoin-based Rollups approach liquidity, borrowing, and collateral across the ecosystem.

What to watch next

• Monitoring ctUSD adoption: tracking on-chain utilization, liquidity depth, and user uptake as ctUSD becomes the standard base liquidity token on Citrea.
• Regulatory and banking integration steps: assessing how MoonPay’s rails and vIBAN-based payments evolve to support broader institutional participation.
• Security and governance developments: evaluating the trust model around the single sequencer, off-chain treasury, and multi-party federation, and how that affects security guarantees.
• Liquidity growth metrics: watching the rate at which BTC-denominated DeFi products and collateralized lending scale beyond the initial $50 million target.
• Industry comparison: observing how Citrea’s approach stacks up against other Bitcoin DeFi initiatives and cross-chain bridges in terms of risk, capital efficiency, and user experience.

Sources & verification

• Citrea mainnet launch announcement and details on the Pr Newswire release documenting BTC collateral lending, BTC-structured products, and ctUSD.
• Statements from Orkun Mahir Kılıç, co-founder and CEO of Chainway Labs, regarding ctUSD being natively issued on the Citrea rollup and wired into MoonPay’s infrastructure (vIBANs).
• Testnet data showing significant data availability usage, illustrating early demand on Bitcoin block space.
• Industry commentary on Bitcoin block space and DeFi use cases, including perspectives from Bitcoin core developers and prominent community members.
• Related industry coverage, including Animoca, RootstockLabs collaboration on Bitcoin DeFi and broader market analyses.

Citrea’s Bitcoin-native DeFi experiment lands on mainnet

Bitcoin (CRYPTO: BTC) stands at the center of Citrea’s ambitious push to reimagine how its network’s scarce resources can power a DeFi stack. The project’s mainnet launch introduces a native BTC-collateral lending framework, BTC‑structured products, and ctUSD (CRYPTO: CTUSD), a stablecoin issued directly on the rollup rather than bridged from another chain. ctUSD is designed to be the core liquidity layer for the Bitcoin economy, backed 1:1 by cash and short‑term US Treasuries, and wired into fiat rails via MoonPay’s infrastructure. The arrangement promises to simplify on‑ramp and settlement flows while anchoring DeFi activity to Bitcoin’s security model.

From the outset, ctUSD is positioned as a compliant counterweight to wrapped versions of other dollars, with the intent of avoiding liquidity fragmentation that can arise when similar assets exist across multiple bridges. The stablecoin’s native issuance aims to minimize cross‑chain risk by keeping collateral and settlement within Citrea’s consolidated ecosystem. In practical terms, ctUSD’s 1:1 backing by cash and Treasuries provides a straightforward, auditable reserve model, and the on‑ramp through traditional rails may appeal to institutions seeking regulated exposure to Bitcoin‑denominated liquidity.

Critical to the project’s architecture is a belief that Bitcoin should not be confined to a single function. Citrea emphasizes that its rollup inherits the security properties of Bitcoin’s base layer, avoiding the common transfer of risk seen in bridging scenarios. Critics caution that the model retains considerable off‑chain trust assumptions, including the role of a single sequencer and a multi‑party federation, which could introduce governance and operational risks even as they simplify certain on‑chain mechanics. The debate over “on‑chain DeFi on Bitcoin” continues, but Citrea’s mainnet provides a concrete, observable milestone that tests whether a Bitcoin‑anchored DeFi layer can deliver sustainable liquidity and reliable settlement.

Early activity on the testnet offered a glimpse into the demand for Bitcoin block space in DeFi contexts. Citrea reported that data availability usage early in the cycle amounted to a meaningful share of Bitcoin’s monthly bandwidth, a signal that even pre‑launch engines can drive real congestion and fee pressure if scaling proves feasible. As the project moves from testnet signals to full mainnet liquidity, observers will be watching how quickly lending, trading, and structured products develop the kind of organic usage that supports miners’ fee revenues without compromising network resilience.

In the broader crypto landscape, Citrea’s approach intersects with a growing appetite for regulated, Bitcoin‑backed financial infrastructure. Proponents argue that a well‑designed, Bitcoin‑anchored DeFi layer could unlock new forms of liquidity for BTC holders, reduce the reliance on non-Bitcoin bridges, and create a more cohesive Bitcoin economy. Skeptics, meanwhile, worry about overloading Bitcoin’s capacity and introduce concerns about centralized trust models. The truth likely lies somewhere in between: if Citrea demonstrates sustained liquidity growth, robust security guarantees, and clear risk controls, it could influence how market participants conceptualize the use of Bitcoin block space for financial dApps rather than payments alone.

The broader narrative continues to unfold as other projects explore Bitcoin DeFi and institutions weigh regulated access to Bitcoin‑denominated liquidity. While opinion remains divided, Citrea’s mainnet provides a real‑world test case for mounting Bitcoin‑centric DeFi activity on a native rollup that’s tightly linked to regulated fiat rails. If ctUSD proves scalable and reliable—and if liquidity grows toward the $50 million target in coming weeks—the model could catalyze further experimentation aimed at harmonizing Bitcoin’s security with a broader, on‑chain financial ecosystem.