If you have spent any time exploring DeFi, you have come across stablecoins. They sit at the centre of almost every yield strategy, lending market, liquidity pool, and cross-chain protocol in the space. Understanding them is not optional. It is the foundation on which everything else in DeFi is built.
This guide explains what stablecoins are, how the two most widely used ones work, where their limitations lie, and why a newer version called USDT0 is worth understanding if you are serious about earning yield across chains.
What Is a Stablecoin?
A stablecoin is a cryptocurrency designed to maintain a stable value, typically pegged to a fiat currency like the US dollar. Unlike Bitcoin or Ethereum, which can fluctuate by double digits in a single day, a stablecoin is intended to always be worth approximately one dollar.
This stability makes stablecoins extremely useful in crypto. They let you stay in the crypto ecosystem without exposure to volatility. You can earn yield, provide liquidity, make transfers, and participate in DeFi protocols without needing to convert back to fiat between every move.
There are different ways to achieve this stability. The most common approach, and the one used by both USDT and USDC, is fiat collateralisation. The issuer holds real-world assets, typically cash and short-term government securities, in reserve and issues tokens on a one-to-one basis against those reserves. Each token in circulation is theoretically backed by one dollar sitting in a bank or treasury account.
USDT: The Largest Stablecoin by Volume
USDT, issued by Tether, is the largest stablecoin in the world by market capitalisation and daily trading volume. It was one of the first stablecoins to achieve widespread adoption and remains the dominant choice for trading, transfers, and DeFi participation across most major blockchains.
How It Works
Tether issues USDT tokens and maintains a reserve of cash, cash equivalents, and other short-term instruments to back each token in circulation. Users can in theory redeem USDT directly with Tether for the equivalent value in fiat, though this process is typically limited to large institutional redemptions.
USDT exists as a separate token deployment on each blockchain it operates on. There is a USDT contract on Ethereum, a separate one on Tron, another on Arbitrum, and so on. Each deployment is independent and moving USDT between chains requires using a bridge.
Why It Is So Widely Used
USDT’s dominance comes from network effects. It is accepted on more exchanges, supported by more protocols, and held by more users than any other stablecoin. When liquidity matters, USDT is usually the deepest market available.
For traders and DeFi users, this depth of liquidity means tighter spreads, lower slippage, and more consistent pricing across platforms.
Its Limitations
Tether has faced scrutiny over the years regarding the composition and transparency of its reserves. While the company publishes quarterly attestations, these fall short of the full audits that some critics and regulators have requested. For users who prioritise maximum transparency from their stablecoin issuer, this is a consideration worth noting.
The multi-chain fragmentation is also a practical limitation. Moving USDT between chains requires bridging infrastructure, which introduces delay, additional transaction costs, and in some cases, counterparty risk from the bridge itself.
USDC: The Regulated Alternative
USDC is issued by Circle, a US-based financial technology company, in partnership with Coinbase. It was created in part as a response to concerns about Tether’s transparency and has positioned itself as the more regulated and auditable stablecoin option.
How It Works
USDC operates on a similar model to USDT. Each token is backed one-to-one by US dollar reserves held in regulated financial institutions. Circle publishes monthly attestations from independent accountants confirming the reserve balances, which are generally considered more transparent than Tether’s disclosures.
Like USDT, USDC exists as separate token deployments on each supported blockchain. Moving it cross-chain requires bridging, with the same associated friction and risks.
Why It Is Popular
USDC has become the preferred stablecoin for institutional participants, regulated entities, and protocols that want a more compliant asset at the centre of their operations. Its adoption in lending protocols, payment applications, and regulated DeFi products has grown significantly since its launch.
Circle also operates a native cross-chain transfer protocol called CCTP, which allows USDC to be moved between supported chains by burning on one chain and minting on another, removing the need for wrapped versions. This is an improvement over traditional bridging, though it still requires specific infrastructure and is limited to supported chains.
Its Limitations
USDC carries regulatory risk. Because Circle is a US-based company subject to US law, USDC can be frozen or blacklisted at the address level if required by authorities. This happened in 2022 when Circle froze USDC held in addresses associated with the Tornado Cash mixer following US Treasury sanctions.
For users who value censorship resistance as a property of their stablecoin, this is a meaningful distinction from more decentralised alternatives.
The Problem Both Share: Cross-Chain Fragmentation
Despite their differences, USDT and USDC share a fundamental architectural limitation. They are designed as single-chain assets that are replicated across multiple chains through bridging or separate deployments.
This creates fragmentation. Consider the following:
- USDT on Ethereum and USDT on Arbitrum are different tokens governed by different contracts
- Moving between them requires a bridge, which locks tokens on one side and mints wrapped representations on the other
- Wrapped versions may trade at slight discounts and carry additional smart contract risk from the bridge itself
- Liquidity is siloed: a deep USDT pool on one chain does not help you if you need liquidity on another
For a user who simply wants to deposit capital and earn yield on a specific chain, this fragmentation means extra steps, extra costs, and extra risk before they even begin.
What Is USDT0 and How Is It Different?
USDT0 is an omnichain version of USDT built on top of LayerZero’s OFT (Omnichain Fungible Token) standard. It is a collaboration between Tether and LayerZero, and it represents a fundamentally different approach to how a stablecoin can exist across multiple blockchains.
One Token Across All Chains
Instead of deploying separate token contracts on each chain, USDT0 is a single unified token standard. It can move between supported chains natively using LayerZero’s cross-chain messaging infrastructure, without being wrapped into a different token on the destination chain.
When you move USDT0 from Ethereum to HyperEVM, you are not receiving a wrapped version of USDT0. You are receiving the same token, transferred via a secure cross-chain message. The asset you hold on the destination chain is identical to the one you sent from the source chain.
No Traditional Bridging Required
Traditional bridges work by locking your tokens in a contract on the source chain and minting new tokens on the destination chain. This means the minted tokens are only as safe as the bridge contract. If the bridge is hacked or the contract fails, the locked tokens can be lost even if you hold the minted tokens on the other side.
USDT0 removes this risk. Because it uses LayerZero’s messaging protocol rather than a lock-and-mint bridge, there is no pool of locked tokens sitting in a bridge contract waiting to be exploited. The cross-chain transfer is handled at the messaging layer, which has a different and in many respects more robust security model.
Unified Liquidity Across Chains
Because USDT0 is the same token regardless of which chain it sits on, liquidity is not fragmented between chain-specific deployments. A protocol that accepts USDT0 can receive deposits from users on any supported chain without needing separate liquidity pools or wrapped token integrations for each chain.
For yield protocols, this is a meaningful infrastructure advantage. It means depositors anywhere on a supported EVM chain can participate without first needing to bridge their assets manually.
Side-by-Side Comparison
Why USDT0 Matters for DeFi Yield
For a protocol like Altura, which operates on HyperEVM and accepts deposits from users across EVM-compatible chains, USDT0 is not just a convenient choice. It is the right architectural fit.
Here is why it matters in practice:
Frictionless Deposits From Any Supported Chain
A user holding USDT on Ethereum can deposit into Altura without manually bridging first. The USDT0 transfer mechanism handles the cross-chain movement in the background. From the depositor’s perspective, the process is straightforward: connect your wallet, deposit, and start earning.
No Wrapped Token Risk
Because USDT0 is not a wrapped representation of another token, depositors are not exposed to the additional smart contract risk that comes with traditional bridged assets. The asset they deposit is the same asset the protocol holds, with no intermediate wrapper layer introducing additional failure points.
Consistent Pricing and Liquidity
USDT0 maintains consistent pricing across chains because it is the same token rather than multiple separate deployments. This means yield calculations, PPS tracking, and withdrawal valuations are straightforward and consistent regardless of which chain a depositor originated from.
Aligned With the Direction of DeFi Infrastructure
The broader DeFi ecosystem is moving toward omnichain infrastructure. The fragmentation of assets across chains is increasingly recognised as a design limitation that creates unnecessary friction, risk, and complexity for users. USDT0 is part of a broader shift toward unified cross-chain asset standards, and protocols built on this infrastructure are better positioned for the next phase of DeFi development.
Which Stablecoin Is Right for You?
The honest answer depends on what you are using it for.
- If you are trading on centralised exchanges or holding stablecoins in a wallet, USDT’s liquidity depth makes it the practical default choice for most users.
- If you are working with regulated protocols, payment applications, or compliant DeFi products, USDC’s transparency and regulatory positioning may make it the better fit.
- If you are depositing into a cross-chain DeFi yield protocol, particularly one operating on HyperEVM, USDT0’s omnichain design removes friction and risk that both USDT and USDC carry when used across chains.
These are not mutually exclusive. Many DeFi users hold all three depending on what they are doing with their capital at a given time.
The Bottom Line
Stablecoins are the foundation of DeFi. Understanding how they work, where their risks lie, and what makes newer designs like USDT0 different is essential knowledge for anyone who wants to use DeFi confidently and safely.
USDT and USDC are well-established, widely supported, and suitable for most general use cases. But as DeFi infrastructure evolves toward omnichain architectures, the limitations of chain-specific stablecoin deployments become more apparent. USDT0 addresses those limitations directly, and for cross-chain yield participation, it is a meaningfully better tool.
To see how USDT0 is used in practice within a multi-strategy yield vault, visit altura.trade and explore how the Altura Yield Engine is built.