Stablecoin

What Is a Stablecoin?

A stablecoin is a type of cryptocurrency designed to maintain a stable value relative to a reference asset, most commonly the US dollar. While cryptocurrencies like Bitcoin and Ethereum can swing 10% or more in a single day, stablecoins aim to hold a consistent 1:1 peg, making them usable as a unit of account, medium of exchange, and store of value within the crypto ecosystem.

The core idea is straightforward: take the benefits of blockchain-based money (programmability, near-instant settlement, 24/7 availability, global reach) and remove the price volatility that makes raw cryptocurrencies impractical for everyday transactions. A merchant accepting Bitcoin faces significant exchange rate risk between the moment of sale and when they convert to fiat. A merchant accepting USDC does not.

Stablecoins have grown from a niche DeFi tool to a cornerstone of the digital economy. By early 2026, the aggregate stablecoin market cap exceeded $317 billion, with over $33 trillion in annual transaction volume during 2025: a 72% year-over-year increase. Two stablecoins, USDT and USDC, account for approximately 92% of that market.

How Stablecoins Work

All stablecoins share the same goal: maintain a 1:1 peg with their reference asset. They diverge dramatically in how they achieve it. The three main categories are fiat-backed, crypto-backed, and algorithmic.

Fiat-Backed Stablecoins

Fiat-backed stablecoins are the simplest model. A centralized issuer holds reserves of real-world assets (cash, bank deposits, short-term US Treasuries) and mints tokens against those reserves on a 1:1 basis. When a user deposits $1, they receive 1 stablecoin. When they redeem 1 stablecoin, they receive $1 back.

The peg is maintained through direct convertibility and arbitrage. If the stablecoin trades below $1 on exchanges, arbitrageurs buy the discounted tokens and redeem them at par from the issuer, pocketing the difference and pushing the market price back up. If it trades above $1, they mint new tokens at par and sell them on the open market.

USDT (Tether) and USDC (Circle) dominate this category. USDT holds roughly $188 billion in market cap as of early 2026, while USDC grew 73% in 2025 to reach approximately $75 billion. Both hold their reserves primarily in US Treasuries and cash equivalents.

Crypto-Backed Stablecoins

Crypto-backed stablecoins replace centralized reserves with overcollateralized smart contract vaults. Users deposit volatile crypto assets (ETH, WBTC, other tokens) worth significantly more than the stablecoins they mint. If the collateral drops in value, the protocol automatically liquidates positions to maintain system solvency.

The most prominent example is DAI (now rebranded to USDS as of April 2026), created by MakerDAO (now Sky). A user depositing $150 worth of ETH can mint up to $100 in USDS. If their collateral ratio drops below the required threshold, any participant can trigger liquidation. This overcollateralization buffer absorbs price swings in the underlying collateral.

The advantage is decentralization: no single entity controls the reserves. The tradeoff is capital inefficiency, since users must lock up more value than they receive. Crypto-backed stablecoins also inherit the risks of their collateral assets and the smart contracts that manage them.

Algorithmic Stablecoins

Algorithmic stablecoins attempt to maintain their peg using supply-adjustment algorithms rather than collateral. When the price rises above $1, the protocol mints new tokens to increase supply and push the price down. When it falls below $1, the protocol contracts supply (typically through burn mechanisms or bond issuance) to push the price up.

This approach is capital-efficient but fragile. The catastrophic collapse of TerraUSD (UST) in May 2022 demonstrated the fundamental vulnerability: a death spiral where loss of confidence triggers mass redemptions, which accelerate the depeg, which triggers more redemptions. The UST/LUNA collapse erased over $50 billion in value in days and inflicted an estimated $400 billion in broader crypto market losses.

Since the UST collapse, purely algorithmic models have fallen out of favor. Most new stablecoin designs incorporate some form of real-world or crypto collateral, recognizing that algorithmic mechanisms alone cannot sustain confidence during stress events.

Use Cases

Payments and Commerce

Stablecoins function as a digital dollar on blockchain rails. They enable near-instant settlement, 24/7 availability, and programmable payment logic. B2B payments represented 62.9% of stablecoin transaction activity in 2025, making business-to-business flows the dominant use case by volume. Stablecoin-powered payment rails are increasingly competitive with traditional card networks: adjusted stablecoin transaction volumes in 2025 reached $10.9 trillion, approaching Visa's $14.2 trillion. For more detail, see this comparison of stablecoin and traditional payment rails.

Cross-Border Remittances

Sending money internationally through traditional banking costs an average of over 6% in fees and can take days. Stablecoins settle in seconds for under $1 in fees, regardless of corridor. This makes them particularly valuable for cross-border payments and remittances to emerging markets where banking access is limited. Services like Sling Money, Felix Pago, and NALA use stablecoins as the settlement layer for consumer remittance flows. Dollar-denominated neobanks in Latin America and Africa use stablecoins to give users access to dollar savings without a US bank account. Learn more about specific corridors in this remittance corridor analysis.

DeFi Infrastructure

Within DeFi, stablecoins are the primary unit of account. They serve as collateral in lending protocols, base pairs in decentralized exchanges, and settlement assets in liquidity pools. Most DeFi yields are denominated in stablecoins because they provide a stable benchmark for measuring returns.

On-Ramps, Off-Ramps, and Dollar Access

Stablecoins serve as the primary bridge between fiat and crypto. Users on-ramp by converting fiat to stablecoins, trade or invest in volatile assets, then off-ramp back to stablecoins when they want stability. In countries with unstable local currencies, dollar-pegged stablecoins provide access to the dollar economy without requiring a US bank account. The global demand for dollar-denominated stablecoins continues to grow, driven by this dollarization use case.

Stablecoins on Bitcoin

Stablecoins are no longer limited to Ethereum and EVM chains. Protocols like Spark enable stablecoin issuance and transfer on Bitcoin's layer-2 ecosystem, bringing dollar-denominated payments to Bitcoin's security model. USDB is one example of a stablecoin native to the Bitcoin ecosystem. For a broader look at this space, see the complete landscape of stablecoins on Bitcoin.

Regulation

Stablecoin regulation has advanced rapidly. Two major frameworks now govern the largest markets:

The GENIUS Act (United States)

The Guiding and Establishing National Innovation for US Stablecoins Act was signed into law on July 18, 2025. It creates the first comprehensive federal framework for payment stablecoins, requiring issuers to maintain 100% reserve backing in liquid assets (US dollars or short-term Treasuries with 93-day maturity or less), redeem tokens within specified timeframes, and publish monthly reserve disclosures. Regulators must finalize implementation rules by July 2026, with enforcement beginning January 2027. For a detailed breakdown, see this GENIUS Act explainer.

MiCA (European Union)

The EU's Markets in Crypto-Assets Regulation took full effect on January 1, 2025. It requires stablecoin issuers to allow redemption at par value at any time, with significant issuers holding 60% of reserves as bank deposits at EU credit institutions. Non-compliant issuers face delisting from EU markets after July 1, 2026. For a global comparison of regulatory approaches, see this regulatory framework analysis.

Risks and Considerations

Depeg Risk

The defining risk of any stablecoin is losing its peg. Historical data shows this is not theoretical: Moody's recorded 1,914 depeg events through mid-2023, 609 involving major stablecoins. The UST collapse (May 2022) was catastrophic and permanent. USDC briefly dropped to $0.87 during the Silicon Valley Bank crisis in March 2023 when $3.3 billion of its reserves were trapped in the failing bank, though it recovered within 48 hours after regulators guaranteed all SVB depositors. These events demonstrate that even well-collateralized stablecoins carry depeg risk during systemic stress.

Reserve Transparency

For fiat-backed stablecoins, the quality and transparency of reserves determines trust. USDC publishes monthly attestations from an independent accounting firm. USDT has faced persistent criticism for less transparent reporting. The GENIUS Act's monthly disclosure requirement aims to establish a floor for reserve transparency, but enforcement has not yet begun. The stablecoin trilemma (stability, decentralization, capital efficiency) means every design involves tradeoffs. For a deeper look, see this reserve transparency analysis.

Regulatory and Compliance Risk

The GENIUS Act and MiCA create incompatible compliance regimes with no mutual recognition. Issuers must maintain separate licenses and reserve programs in each jurisdiction, creating operational complexity. Stablecoins can also face blacklisting if addresses are associated with sanctioned entities. Centralized issuers like Circle and Tether can freeze tokens on specific addresses, which creates censorship risk but satisfies regulatory requirements.

Smart Contract and Technical Risk

Crypto-backed stablecoins depend on smart contracts for collateral management, liquidation, and governance. Bugs, exploits, or governance attacks can drain funds. Even audited contracts represent point-in-time reviews rather than ongoing guarantees. Protocol risk compounds when stablecoins serve as collateral for other protocols: the USDC depeg in March 2023 triggered a contagion depeg in DAI because over 50% of DAI's collateral was denominated in USDC.

Concentration Risk

With USDT and USDC representing roughly 92% of the total stablecoin market cap, a major failure in either would have systemic consequences across the entire crypto ecosystem. This concentration is slowly improving as new entrants like PYUSD, EURC, and various regulated issuers enter the market, but the duopoly remains dominant.

This glossary entry is for informational purposes only and does not constitute financial or investment advice. Always do your own research before using any protocol or technology.