What is a Stablecoin? USDT, USDC, and How They Work

Summary:

• A stablecoin is a cryptocurrency designed to hold a steady value, usually pegged to the U.S. dollar, unlike volatile assets such as Bitcoin or Ethereum.
• The three main models are fiat-collateralized, crypto-collateralized, and algorithmic, with fiat-backed coins like USDT and USDC now the industry standard.
• USDT (Tether) is the largest stablecoin by market cap, while USDC (Circle) has built its reputation on regulatory transparency and monthly reserve attestations.
• Newer entrants like USD1 and DAI use different backing models, and XRP, despite common confusion, is not a stablecoin at all.
• The GENIUS Act, signed into law in 2025, created the first U.S. federal framework for stablecoins, though detailed rules are still being finalized in 2026.

Cryptocurrency has a reputation for volatility, but a huge chunk of the crypto market is actually built around avoiding it. Stablecoins are designed to hold a steady value, usually pegged to the U.S. dollar, and they’ve become one of the most widely used tools in crypto, from trading to everyday payments. Here’s what they are and how the major ones work.

What is a Stablecoin?

A stablecoin is a type of cryptocurrency designed to maintain a stable price, typically by pegging its value to a traditional currency like the U.S. dollar, or occasionally to a commodity like gold. Unlike Bitcoin or Ethereum, whose prices can swing sharply within hours, a well-functioning stablecoin is meant to stay close to $1.00 (or whatever asset it tracks) at all times.

That stability is what makes stablecoins useful. They let people move value across the crypto ecosystem, trade between different tokens, or send money internationally, without taking on the price risk of a volatile asset in the process.

How Do Stablecoins Stay Stable?

Different stablecoins use different mechanisms to hold their peg. The three main approaches are:

• Fiat-collateralized. The issuer holds real dollars (or equivalent assets like short-term U.S. Treasury bills) in reserve, equal to the amount of stablecoin in circulation. Each token can, in theory, be redeemed for the underlying dollar. USDT and USDC both work this way.
• Crypto-collateralized. The stablecoin is backed by other cryptocurrencies instead of fiat, typically over-collateralized to absorb price swings in the underlying assets. DAI is the best-known example.
• Algorithmic. The peg is maintained through code and market incentives rather than a reserve of assets. This model has a rockier history. Several algorithmic stablecoins have “de-pegged” and collapsed in the past, which is why the fiat-backed model has become the industry standard for anything positioning itself as low-risk.

USDT (Tether): The Largest Stablecoin

USDT, issued by Tether, is the largest stablecoin by market capitalization and one of the most heavily traded assets in all of crypto. It’s used extensively on exchanges as a trading pair and as a way to move value between platforms quickly. Tether publishes periodic attestations about its reserves, though it has faced scrutiny over the years regarding reserve transparency and composition.

USDC (USD Coin): The Regulated Alternative

USDC is issued by Circle and has built its reputation around regulatory compliance and transparency. Circle publishes monthly attestation reports on USDC’s reserves, which are held in cash and short-term U.S. Treasuries, and has positioned USDC as the stablecoin of choice for institutions and regulated businesses. USDC runs on Ethereum and several other blockchains, making it widely accessible across the crypto ecosystem.

Other Stablecoins Worth Knowing

• USD1, issued by World Liberty Financial, is a newer dollar-pegged stablecoin backed by cash and short-term Treasuries, held in custody by BitGo Trust Company. It launched in 2025 and grew quickly, reaching billions of dollars in circulating supply within its first year.
• DAI, issued by the decentralized protocol MakerDAO, is backed by a mix of crypto collateral rather than direct fiat reserves, making it a different model from USDT, USDC, or USD1.

Is XRP a Stablecoin?

No. XRP is not a stablecoin. It’s a cryptocurrency that trades on the open market, and its price fluctuates like any other digital asset. It isn’t pegged to the dollar or any other fixed value. Stablecoins and XRP are sometimes confused because both are frequently used for fast, low-cost payments, but their price behavior is fundamentally different.

Stablecoin Regulation: The GENIUS Act

For years, U.S. stablecoins operated in a regulatory gray area. That changed with the GENIUS Act, signed into law in July 2025, which created the first federal framework specifically for payment stablecoins. The law establishes rules for who can issue a “permitted payment stablecoin,” how reserves must be held, and which federal agencies (including the OCC, FDIC, and Federal Reserve) oversee different types of issuers.

As of 2026, regulators are still finalizing the detailed rules required under the law, and the framework is expected to take full effect on a rolling basis as agencies complete their rulemaking. In the meantime, several states, including Wyoming and New York, continue to operate their own stablecoin licensing regimes alongside the emerging federal system.

Risks to Understand

Stablecoins are lower-risk than volatile cryptocurrencies, but “stable” doesn’t mean risk-free:

• De-pegging. In rare cases, a stablecoin can lose its peg, either briefly or permanently, if confidence in its reserves is shaken or if its stabilization mechanism fails.
• Reserve quality and transparency. Not all issuers disclose their reserves with the same level of detail or auditing rigor, so the backing behind two dollar-pegged stablecoins isn’t always equivalent.
• Counterparty and custody risk. Because most stablecoins are issued by a private company, holders are relying on that company’s solvency and honesty, not a government guarantee like FDIC deposit insurance.

Is Investing in Stablecoins a Good Idea?

That depends on what you’re using them for. Because their whole design goal is price stability rather than growth, stablecoins aren’t typically used as a speculative investment the way Bitcoin or Ethereum are. They’re more commonly used as a stable “parking spot” for funds within the crypto ecosystem, for payments, or as a bridge between different currencies and platforms.

As with any financial decision, it’s worth researching a specific stablecoin’s reserve backing and regulatory status before relying on it, and this article is for educational purposes only, not financial advice.

Quick FAQ

Are stablecoins really worth exactly $1? Most stay very close to $1, but small deviations happen, and in rare cases a stablecoin can de-peg significantly.

Can I use stablecoins to buy things? Yes, stablecoins like USDT and USDC are increasingly accepted for payments, including for digital gift cards.

Is USDT the same as USDC? No. Both are dollar-pegged stablecoins, but they’re issued by different companies (Tether and Circle) with different reserve compositions and levels of regulatory disclosure.

Are stablecoins regulated? In the U.S., yes, as of the GENIUS Act signed into law in 2025, though the detailed rules are still being finalized by federal regulators.