Stablecoins: How They Work and Why They Matter
Stablecoins occupy a distinct position in the digital currency landscape — they are blockchain-based tokens engineered to hold a consistent value, typically pegged to a fiat currency such as the US dollar. Understanding how stablecoins achieve price stability, what risks each design introduces, and how US regulators have framed their oversight is essential for anyone operating in the digital currency ecosystem. This page covers the definition and classification of stablecoins, the technical mechanisms that maintain their pegs, the practical contexts in which they are deployed, and the decision boundaries that separate one stablecoin type from another.
Definition and scope
A stablecoin is a digital asset designed to maintain price parity with a reference asset — most commonly the US dollar, though pegs to the euro, gold, and commodity baskets also exist. Unlike Bitcoin or Ether, whose market prices float freely, stablecoins subordinate price discovery to a stability mechanism, making them functionally closer to a digital representation of fiat money than to speculative assets.
The Financial Stability Board (FSB) defines stablecoins in its 2022 report on the regulation of crypto-asset markets as crypto-assets that aim to maintain a stable value relative to a specified asset or pool of assets. The President's Working Group on Financial Markets, the FDIC, and the OCC jointly published a 2021 report on stablecoins that estimated stablecoin market capitalization had grown to approximately $127 billion by October 2021, underscoring the systemic significance of these instruments.
The regulatory context for digital currency in the US treats stablecoins differently from other tokens depending on their design, the nature of their reserves, and whether they function as payment instruments, securities, or money market equivalents.
How it works
Stablecoins achieve price stability through 3 distinct structural mechanisms. Each mechanism creates a different risk profile and requires different governance architecture.
1. Fiat-Collateralized Stablecoins
The issuer holds reserve assets — cash, short-term Treasuries, or cash equivalents — equal to or exceeding the outstanding supply of tokens. Each token is redeemable one-for-one against the reserve. Tether (USDT) and USD Coin (USDC) operate on this model. Stability depends on the completeness and liquidity of reserves and on auditor attestations confirming reserve adequacy. The Office of the Comptroller of the Currency (OCC) issued Interpretive Letter 1174 in 2021, confirming that national banks may hold stablecoin reserves and participate in stablecoin networks.
2. Crypto-Collateralized Stablecoins
Reserves consist of other cryptocurrencies rather than fiat. Because crypto collateral is volatile, these systems are over-collateralized — a user may deposit $150 in Ether to mint $100 in stablecoins, creating a 150% collateralization ratio. If collateral value falls below a liquidation threshold, smart contracts automatically sell the collateral. MakerDAO's DAI uses this mechanism. The primary risk is collateral cascade failure during broad market drawdowns.
3. Algorithmic (Non-Collateralized) Stablecoins
Stability is maintained through algorithmic supply adjustments — expanding supply when price exceeds the peg, contracting it when price falls below. Some implementations use a two-token model: a stablecoin paired with a governance or seigniorage token. The collapse of TerraUSD (UST) in May 2022, which lost its $1 peg and wiped out approximately $40 billion in market value within 72 hours (FSB, Crypto-Asset Markets: Potential Channels for Future Financial Stability Implications), demonstrated the reflexive failure mode inherent to purely algorithmic designs.
The Redemption Mechanism
Across all collateralized models, the peg holds through arbitrage: if the token trades below $1.00, arbitrageurs buy tokens at a discount and redeem them at par, reducing supply and lifting price. If the token trades above $1.00, new tokens are minted and sold, expanding supply and pushing price back to parity. This mechanism requires a credible, liquid redemption window — its absence is a primary indicator of systemic risk.
Common scenarios
Stablecoins serve 4 primary functional roles in practice:
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Trading pair settlement: Exchanges use stablecoins as base pairs, allowing traders to exit volatile positions without converting to fiat and incurring banking delays. USDT is the highest-volume trading pair on centralized exchanges by dollar volume.
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Cross-border remittances: Dollar-pegged stablecoins enable near-instant international transfers at a fraction of traditional wire costs. The World Bank's Remittance Prices Worldwide database documents average global remittance costs consistently above 6%, a gap that stablecoin corridors are structured to reduce.
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Decentralized finance (DeFi) liquidity: Stablecoins serve as the primary denomination for lending, borrowing, and yield protocols within decentralized finance ecosystems. Protocols such as Aave and Compound use stablecoins as collateral and payout currency.
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Business treasury management: Companies holding digital assets use stablecoins as a low-volatility parking instrument between transactions, particularly in jurisdictions where banking access to crypto businesses is restricted.
Decision boundaries
Selecting or evaluating a stablecoin requires mapping it against 5 structural criteria:
| Criterion | Fiat-Collateralized | Crypto-Collateralized | Algorithmic |
|---|---|---|---|
| Reserve transparency | Dependent on audits | On-chain, verifiable | No reserve |
| Peg failure risk | Low if reserves are full | Medium (liquidation risk) | High (reflexive collapse) |
| Counterparty exposure | Issuer and custodian | Smart contract code | Governance token holders |
| Regulatory classification | Payment instrument | Potentially a security | Typically unclassified |
| Capital efficiency | 1:1 (inefficient) | ~1.5:1 (over-collateralized) | Theoretically 1:1 |
The distinction between fiat-collateralized and algorithmic designs is not merely technical — it carries regulatory weight. The FSB's 2023 recommendations for global stablecoin oversight, published in FSB High-Level Recommendations for the Regulation, Supervision and Oversight of Global Stablecoin Arrangements, specifically call for redemption rights, reserve asset quality requirements, and governance standards that algorithmic models structurally cannot satisfy.
In the US, the regulatory classification of a stablecoin also determines the applicable enforcement body. Stablecoins functioning as payment instruments fall under potential jurisdiction of the Federal Reserve, OCC, or state money transmitter licensing regimes. Those structured with profit-sharing features may meet the Howey test thresholds applied by the Securities and Exchange Commission (SEC). The Commodity Futures Trading Commission (CFTC) has asserted jurisdiction over stablecoins used in derivatives contexts. This multi-agency overlap is a defining feature of the US regulatory landscape for digital currency.
Issuers and institutional holders also face Bank Secrecy Act (BSA) obligations under 31 U.S.C. § 5311 et seq., requiring Anti-Money Laundering (AML) programs, Know Your Customer (KYC) procedures, and Suspicious Activity Report (SAR) filings — obligations enforced by FinCEN (FinCEN Guidance FIN-2019-G001).
References
- Financial Stability Board — Assessment of Risks to Financial Stability from Crypto-Assets (2022)
- FSB — High-Level Recommendations for the Regulation, Supervision and Oversight of Global Stablecoin Arrangements (2023)
- President's Working Group on Financial Markets, FDIC, OCC — Report on Stablecoins (2021)
- OCC Interpretive Letter 1174 (2021)
- FinCEN Guidance FIN-2019-G001 — Application of FinCEN's Regulations to Certain Business Models Involving Convertible Virtual Currencies
- World Bank — Remittance Prices Worldwide Database
- [Bank Secrecy Act — 31 U.S