What Is a Stablecoin? How Pegs, Reserves and Freezes Work

Editor’s take (Keshav Aggarwal): Stablecoins are the digital money for the crypto economy without that it is nearly impossible to get the large volume in the crypto space to trade

What is a stablecoin? It is a cryptocurrency designed to hold a steady value against a reference asset — most often a fiat currency such as the US dollar, but sometimes a commodity, a basket of assets or another cryptocurrency — using reserve assets or algorithms that match supply with demand, according to Wikipedia. The label promises more than the technology guarantees: stablecoins are not necessarily stable, and multiple issuers have failed to hold their peg.

Stablecoins emerged in 2014 as a way for crypto investors to park funds outside volatile tokens. They now sit at the center of crypto trading and cross-border payments. The Financial Action Task Force (FATF) put the sector’s market capitalization at $316 billion in October 2025, with daily trading volume of $156 billion.

What Is a Stablecoin? The Plain Definition

Two design choices define any stablecoin: what backs it, and who can change its supply. Backing can be fiat-denominated assets held by a third-party custodian, other cryptocurrencies locked in a smart contract, commodities, or nothing at all beyond an algorithm. Supply control sits either with a central issuer or with on-chain code.

According to FATF, 95% of stablecoins are backed by fiat currency, and 97% of those fiat-backed coins are denominated in US dollars. That dollar dominance is why stablecoin policy debates are usually debates about the reach of the US dollar.

How reserves and redemption work

In a fiat-backed model, a user sends dollars to the issuer, the issuer mints tokens and places the dollars with a custodian, typically invested in short-term, high-quality instruments: Treasury bonds, high-quality commercial paper, repurchase agreements and bank deposits. To exit, the holder redeems tokens with the issuer and receives dollars back, normally at par and on the issuer’s terms, while other holders buy and sell on the secondary market at whatever price the order book gives.

That structure closely resembles a money market fund, and it carries the same core vulnerability: if enough holders redeem at once, the issuer has to sell reserves into a falling market, and losses can spread to the wider financial system. Redemption terms — minimum sizes, fees, gates, settlement delays — matter as much as the reserve itself.

The four main stablecoin models

Fiat-backed stablecoins

The largest category by far. Tether’s USDT and Circle’s USDC are the best-known dollar examples; on the euro side, Circle’s EURC, EUR Tether and Stasis EUR. The peg is defended by the quality and liquidity of the reserve, and by the issuer’s willingness to redeem. Holders are trusting a company, a custodian and a bank — not code.

Cryptocurrency-backed stablecoins

These use other cryptocurrencies as collateral and rely on smart contracts to track a target price, usually the dollar, as closely as a decentralized network can. Their weakness is collateral volatility: if the backing asset falls faster than the contract can liquidate, the peg follows. A second use is mechanical — converting a cryptocurrency into an ERC-20 compatible standard so it can trade on another blockchain.

Algorithmic stablecoins

Sometimes called seigniorage-style coins, these hold no reserves or only partial reserves and use algorithms to match supply with demand. The European Central Bank has argued they should be treated as unbacked crypto-assets. Examples cited include Celo Dollar, Tron’s USDD and Kava’s USDX.

Commodity-backed stablecoins

A smaller group pegged to metals and other commodities. PAX Gold and Tether Gold are the standard examples.

What Is a Stablecoin Used For?

Trading comes first. Planet Money has compared them to casino chips: a simple way to move in and out of volatile tokens before eventually cashing out.

Payments come second, and they are growing. A 2025 IMF report found stablecoin cross-border flows overtook those of unbacked crypto assets in early 2022 and reached an estimated $1.4 trillion in 2024 — small next to a global cross-border payments market of roughly one quadrillion dollars, but concentrated in emerging markets and developing economies. A University of Cambridge study found the most cited reason for using stablecoins in cross-border settlement is 24/7 settlement outside banking hours. In a 2025 study in the journal Telematics and Informatics of 866 US adults who had sent remittances in the previous year, 26% said they had used stablecoins for cross-border transfers.

Currency substitution and aid distribution are the other live use cases. Chainalysis has documented Venezuelans using dollar-denominated stablecoins to preserve value against bolivar volatility, and by January 2026 dollar stablecoins were reported to be increasingly used in domestic transactions there amid prolonged hyperinflation, sanctions and capital controls. Oxfam has distributed humanitarian aid in Vanuatu with dollar stablecoins since 2019, registering 35,000 people in the Pacific region and distributing around $2 million by 2022. The UNDP reported in January 2026 on pilot programs in Colombia, Syria, Gambia, Papua New Guinea, Kazakhstan and Morocco; in Syria it is testing stablecoin stipends where the financial infrastructure cannot support cash-for-work payments. Portuguese nonprofit ImpactMarket reported distributing over $1 million in Celo Dollar stablecoins to more than 18,000 beneficiaries across 102 African locations.

Depeg risk: when the peg breaks

Historically, multiple stablecoins have failed to maintain their value relative to the underlying asset. The failure modes differ by model. Fiat-backed coins break when reserves are smaller, less liquid or riskier than advertised, or when redemption slows at the worst possible moment. Crypto-backed coins break when collateral falls faster than the contract can respond. Algorithmic coins break when the algorithm meets a market that has stopped believing it.

The contagion channel is the same one that worries regulators about money market funds: a large redemption request forces asset sales, which pushes prices down, which triggers more redemptions. Stablecoin runs are therefore a financial stability question, not only a crypto one.

Freeze risk: who can stop a payment

Fiat-backed stablecoins are issued and redeemed by a central issuer that holds reserve assets with a third-party custodian. That structure means a holder’s access to funds can depend on the issuer’s policies and solvency, not solely on possession of the token. The sources cited here do not detail individual freeze or blacklist events, but they do show that issuers face pressure from regulators, law enforcement and sanctions authorities.

FATF has reported that stablecoins such as USDT and USDC are used for money laundering, terrorism financing and sanctions evasion, which increases the likelihood that issuers will face demands to block or restrict specific balances. The exact freeze powers vary by token contract and jurisdiction, and the sources for this explainer do not provide incident-level figures.

Compliance controls for stablecoin payments

FATF has reported that stablecoins are increasingly used for illicit financial activity, including money laundering, terrorism financing, sanctions evasion and proliferation financing, citing their liquidity, interoperability and ease of cross-border transfer — and noting that USDT and USDC offer a more stable medium than volatile crypto for moving proceeds. In January 2024, the UN Office on Drugs and Crime said stablecoins, particularly USDT, had become the cryptocurrency of choice for organized crime groups engaged in cyberfraud and money laundering in East and Southeast Asia. Reuters reported in 2023 that groups designated as terrorist organizations by Israel, the United States and others were using stablecoins on the Tron blockchain instead of more volatile bitcoin to preserve the value of transferred funds.

The practical consequence for anyone building stablecoin payment flows: identity checks at onboarding and redemption, sanctions screening against wallet addresses at every hop, transaction monitoring tuned for high-velocity cross-border transfers, record-keeping that survives a law enforcement request, and a documented policy for what happens when an issuer is asked to freeze funds. Because the issuer may be able to freeze or restrict balances under its terms or applicable law, the issuer’s compliance posture becomes part of the payment provider’s own risk.

Regulatory scrutiny and monetary sovereignty

Issuance and usage are increasingly regulated by governments around the world. After the United States passed the GENIUS Act, Jürgen Schaaf, an adviser to the European Central Bank, wrote that widespread adoption of US dollar stablecoins could erode European monetary sovereignty and financial stability. Scholars in China and Singapore both described the law as a strategic move to increase demand for US Treasuries and consolidate the hegemony of the dollar. Lesetja Kganyago, governor of the South African Reserve Bank, said dollar stablecoins are being used to undermine African currencies, and Banque de France officials Agnès Bénassy-Quéré and François Villeroy de Galhau warned that Europe’s monetary sovereignty is threatened by dollar-denominated stablecoins. Standard Chartered has warned that up to $1 trillion could flow from developing countries into stablecoins, causing a loss of bank deposits.

Where stablecoins sit in the market

The market is large and unusually concentrated. The Bank for International Settlements said in July 2025 that 90% of stablecoin market capitalization was in Tether or USDC. Concentration cuts both ways: it makes the dollar peg a two-company question, and it means trouble at a single issuer’s reserves would be a systemic event for crypto markets and a serious one for the payment corridors that depend on those tokens.

What to watch: reserve composition and redemption terms at the two dominant issuers, how the GENIUS Act framework is implemented in practice, whether euro-denominated issuance grows, and how freeze and blacklist policies are disclosed to the businesses that rely on these tokens.

Stablecoin glossary: quick recap

• Stablecoin — a cryptocurrency designed to hold a stable value against a reference asset; stable in intent, not guaranteed in practice.
• Peg — the target value, typically $1 for dollar stablecoins.
• Reserve — the assets held to back tokens; for fiat-backed coins, typically short-term government debt, commercial paper, repos and deposits held with a custodian.
• Redemption — exchanging tokens with the issuer for the underlying asset, normally at par and on the issuer’s terms.
• Depeg — a break from the target value.
• Freeze / blacklist — a possible issuer power to block, burn or refuse to redeem specific balances; the exact powers depend on the token contract and applicable law.
• Algorithmic (seigniorage-style) stablecoin — a coin with no or partial reserves that manages supply to hold a price; the ECB treats these as unbacked crypto-assets.
• Money market fund comparison — the structural analogy for fiat-backed coins, run risk included.

Frequently asked questions

Are stablecoins actually stable?

Not automatically. Despite the name, stablecoins rely on reserve assets or algorithms to hold a value, and historically multiple stablecoins have failed to maintain their value relative to the underlying asset. The peg is a design target backed by collateral or code, not a guarantee.

What happens when a stablecoin depegs?

The token trades away from its target on the secondary market. Fiat-backed coins usually break when reserves turn out to be smaller, less liquid or riskier than advertised, or when redemption slows. Large redemption requests force reserve sales, which can push prices down further and trigger more redemptions — the same contagion pattern regulators watch for in money market funds.

Can a stablecoin issuer freeze my funds?

A fiat-backed stablecoin is issued and redeemed by a central issuer that holds reserve assets with a third-party custodian. Whether the issuer can block, burn or refuse to redeem specific balances depends on the token contract and applicable law; the sources used for this explainer do not detail individual freeze events. Holders face counterparty risk separate from price risk.

Source: Wikipedia