What Is a Stablecoin? How Fiat-Backed, Crypto-Backed and Algorithmic Coins Work

Stablecoins are crypto tokens designed to maintain a predictable value, often around one US dollar. If you've been wondering what a stablecoin is and why banks, payment companies and regulators suddenly care so much, the short answer is speed. A traditional wire transfer that takes several business days may be replaced by a stablecoin transfer that settles in minutes, including on weekends. We build payment tools on top of stablecoins at Cybrid, so this page leans practical.

Stablecoin definition: what the term means

A stablecoin definition that holds up: a cryptocurrency pegged to another asset, usually the US dollar, sometimes the euro or gold. The token travels over a blockchain at any hour, and an issuer or a protocol is on the hook for keeping its price near the peg.

People searching for a stablecoin definition may expect something exotic. It rarely is. Think of a receipt for a dollar that lives in a bank account or in short-term government bonds. You can hand the receipt to anyone and normally trade it back for the dollar.

Bitcoin and Ether swing with demand, sometimes within the hour. Stablecoins exist to avoid that. They do it with reserves, with collateral, or with code that adjusts the supply.

How stablecoins keep their peg

Fiat-backed stablecoins

The issuer holds cash and short-term government securities and mints one token per dollar. Holders can redeem tokens for dollars through the issuer or an approved partner. USDT and USDC both work this way, and how USDC gets created and redeemed is laid out in our piece on how USDC is minted and redeemed.

Crypto-backed stablecoins

Other crypto, locked in smart contracts, stands behind these coins. Crypto can lose 30 percent in a day, so the system locks up more value than it issues. The jargon for that is overcollateralization. The dai stablecoin is the standard example: lock Ether in a vault, borrow DAI against it. DAI sits inside the Sky ecosystem now, though the mechanics barely changed.

Algorithmic stablecoins

Some designs skip reserves and use code to expand or shrink supply. This is the group that gave stablecoins a bad name. TerraUSD lost its peg in May 2022 and tens of billions of dollars in value disappeared within days. The long version is in our guide to algorithmic stablecoins.

How stablecoins hold their value day to day

Arbitrage does the heavy lifting. If a coin dips under a dollar, approved traders buy it cheap and redeem it with the issuer for a full dollar, which pulls the price back up. If it trades above a dollar, they pay the issuer a dollar, receive a fresh token and sell it, and the price falls. Only approved partners can usually deal with the issuer directly, so ordinary users buy and sell on exchanges.

What sits in the reserve matters more than the mechanism. According to Circle, USDC reserves are held in cash and short-term US Treasuries, and the company publishes regular reserve reports. Tether publishes attestations for USDT. Ten minutes with one of those reports tells you more than any marketing page.

A stablecoin list worth knowing

Any stablecoin list is out of date within months, so use this as a starting point. USDT from Tether is the biggest by market value. USDC comes from Circle. DAI is the crypto-backed one. PYUSD is a dollar coin that Paxos issues for PayPal.

Stablecoin market cap

Stablecoin market cap is the combined value of all tokens in circulation, a rough measure of how many dollars live onchain. DefiLlama and CoinGecko publish live figures, and USDT and USDC make up most of the total. We won't print a number here. It would be wrong by the time you read it.

Is Bitcoin or Ethereum a stablecoin?

No to both. Is Bitcoin a stablecoin? Nothing pegs it to anything, and it has moved by double digits within a single week more than once. In a stablecoin vs. Bitcoin comparison, one is a volatile asset people trade or hold for years, and the other is something you can price an invoice in.

Is Ethereum a stablecoin? Same answer. Ether is the native token of the Ethereum network and pays its fees. The confusion exists because so many stablecoins run on Ethereum.

What people use stablecoins for

Traders move funds between exchanges. Families send money home. Companies pay contractors and run payroll. People in countries with weak currencies hold them as digital dollars. Which of these jobs you care about decides which coin, chain and partners are worth a look.

How a stablecoin payment works

A company wants to pay a freelancer abroad. It sends stablecoins from a wallet or custody account to the freelancer's address, the network validates the transfer and writes it to the blockchain, and that usually takes seconds or minutes. The freelancer keeps the coins, spends them or redeems them for local currency through a provider.

No chain of correspondent banks sits in between, which is the appeal. The weak spot is at the edges: both sides need a way to convert between bank money and stablecoins, and that's what on-ramps and off-ramps do.

Why businesses use stablecoins

Settlement takes minutes, nights and weekends included. Fees are often lower than the stack of charges behind an international wire. Funds stay in dollars, so there's no exposure to other crypto prices. Software can trigger transfers too, which finance teams like.

The stablecoin itself is rarely the hardest part. Connecting it to bank accounts, wallets and compliance checks is. That's what our stablecoin liquidity, settlement and treasury tools handle, moving funds between fiat and stablecoins, and what our stablecoin infrastructure for B2B payments give companies that pay suppliers abroad through one API.

Stablecoin yield: where it comes from

Stablecoin yield is a return paid for holding or lending a stablecoin. The token itself pays nothing. The money comes from elsewhere: a lending platform passing on borrower interest, a liquidity pool in decentralized finance, an app sharing what it earns on reserves.

Bigger yield means bigger risk, because the funds are being lent or invested and a failure can wipe out principal. The US GENIUS Act bars issuers of payment stablecoins from paying interest to holders directly. Whether exchanges and other partners may offer rewards is still being fought over.

Stablecoin regulation: where things stand

Stablecoin regulation has moved from proposals to law. The US GENIUS Act, signed in July 2025, sets a federal framework for payment stablecoins, with reserve and redemption rules. Agencies are still drafting the details, and the law takes effect no later than January 2027.

Europe moved first. The EU's MiCA regulation has covered stablecoins since 2024, under the labels e-money tokens and asset-referenced tokens. For a company using stablecoins it comes down to two questions: which coins can we use, and which licenses do our partners need?

Risks to understand before you use stablecoins

A depeg is the obvious risk. In March 2023 USDC dropped below a dollar after Circle said part of its cash reserves, about $3.3 billion, sat at Silicon Valley Bank. It recovered once the bank's depositors were protected.

Reserve quality comes second, because cash and short-term Treasuries beat loans or volatile assets. Then there's the issuer, who has to honor redemptions, smart contract bugs in crypto-backed and algorithmic designs, and rules that differ by country. The Bank for International Settlements has argued in its annual reporting that stablecoins fall short of some tests of sound money, which helps explain why regulators want clear reserve and redemption rules. Governments are building digital money of their own too, and CBDC vs stablecoins compares the two.

How to choose a stablecoin

Read the latest reserve report and see what's in it. Check who licenses and regulates the issuer. Confirm the coin runs on the chains you need and has deep liquidity. Compare redemption terms and fees. And ask whether your wallet, custody and compliance partners support it, because a coin nobody around you can handle is no use.

Frequently asked questions

Is a stablecoin the same as a cryptocurrency?

Technically it's a type of cryptocurrency, but it behaves nothing like Bitcoin or Ether. It's built to hold a fixed value, which suits payments and settlement. Most other crypto assets are bought for their price moves.

Can a stablecoin lose its value?

Yes, and it has happened. A coin can trade below its peg when people doubt the reserves or the design. USDC slipped briefly in March 2023, and TerraUSD lost its peg for good in 2022. Reserve-backed coins with clear reports carry less risk.

Are stablecoins legal in the United States?

Holding and using them is legal. The GENIUS Act adds a federal framework for issuers covering reserves, redemption and licensing. Companies that move stablecoins for customers still need the right money transmitter licenses and compliance programs.

What is the safest type of stablecoin?

None is risk free. Fully reserved fiat-backed coins that publish regular reserve reports and answer to a clear regulator are generally seen as lower risk than algorithmic coins, which lean on market incentives to hold the peg.

How do I buy a stablecoin?

Most people use a crypto exchange or a payment provider and pay by bank transfer or card. Businesses can also receive stablecoins straight from a counterparty, or turn fiat into a wallet balance through an on-ramp provider.

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