Stablecoins are the quiet workhorses of the crypto world. They are tokens designed to hold a steady value, usually one US dollar, and they are used for trading, payments, lending and as a safe harbour when the rest of the market is falling. Most crypto trading happens against stablecoins, most DeFi lending uses them, and most traders hold them between trades. Yet the word stable can be misleading. Stablecoins are only as stable as the reserves and mechanisms behind them, and several have lost their peg with serious consequences. This guide explains how the biggest stablecoins work and where the risks hide.

What a stablecoin is

A stablecoin is a cryptocurrency whose value is pegged to another asset, almost always the US dollar. One token is meant to be worth one dollar, at all times, so traders can move in and out of volatile crypto without converting back to traditional money. The two largest stablecoins, USDT, issued by Tether, and USDC, issued by Circle, are both backed by reserves: the issuer holds dollars and other assets that are meant to match the number of tokens in circulation. When you buy one USDT, the idea is that Tether holds one dollar of reserves somewhere to back it. That backing is the whole foundation of the peg.

How USDT and USDC maintain their peg

The peg is maintained by redemption. If you hold USDT or USDC, you can in principle redeem it with the issuer for one dollar, which keeps the market price close to one dollar, because any gap creates an opportunity for traders to profit by buying cheap and redeeming at full value. In practice, most people never redeem directly. They trade the token on exchanges, where the price stays near a dollar because of this arbitrage and because of confidence in the reserves. USDC publishes regular attestations of its reserves from an accounting firm, and its reserves are held mostly in cash and short-term US government securities. Tether also publishes reserve reports, though its holdings have historically included a wider mix of assets, which is why its transparency is debated more often.

The main types of stablecoins

Not all stablecoins work the same way. Fiat-backed stablecoins like USDT and USDC hold real-world reserves and are the largest and most widely used. Crypto-backed stablecoins are backed by other cryptocurrencies held as collateral, usually over-collateralised to absorb price swings. Algorithmic stablecoins hold no reserves at all and try to maintain the peg with code, by expanding or contracting supply, and these have the worst track record: the collapse of TerraUSD in 2022 wiped out tens of billions of dollars and showed that an algorithmic peg can fail completely. For beginners, the lesson is clear: prefer fiat-backed stablecoins from established issuers, and treat algorithmic designs with extreme caution.

The risks: depegging, reserves and regulation

The biggest risk is depegging, when a stablecoin falls below its dollar value. This can happen if the market loses confidence in the reserves, if the issuer faces legal trouble, or if a large holder sells suddenly. USDT and USDC have both traded below a dollar during moments of stress, though they recovered. A second risk is counterparty risk: you are trusting the issuer to hold the reserves honestly and to honour redemptions, and that trust has limits. A third risk is regulatory: governments are writing new rules for stablecoins, and a rule change could freeze redemptions or force an issuer to change its reserves. None of these risks means stablecoins are unsafe to use, but they mean stable is a goal, not a guarantee.

How traders actually use stablecoins

Traders use stablecoins in three main ways. First, as a parking spot: selling volatile crypto for a stablecoin during a downturn, without leaving the crypto ecosystem. Second, as trading pairs: most crypto is bought and sold against USDT or USDC, because pricing in dollars is simpler than pricing in Bitcoin. Third, as fuel for DeFi: lending stablecoins, providing stablecoin liquidity, and earning yield on them. The practical rule is to keep stablecoin holdings diversified across more than one issuer, to check the reserve reports occasionally, and to remember that a stablecoin is a claim on an issuer, not a dollar in your bank account.

Stablecoins in 2026: what to watch

Stablecoins have become central to crypto and are attracting serious regulatory attention. New rules in major markets now require issuers to hold high-quality reserves and to publish regular reports, which is good for users. At the same time, competition is growing, with banks and payment companies launching their own stablecoins, and central banks exploring digital currencies of their own. For a beginner, the practical advice has not changed: use established, fiat-backed stablecoins, understand that the peg depends on trust in the issuer, and never hold your entire balance in a single stablecoin. A stablecoin is a useful tool, not a risk-free asset. This article is educational only and is not financial advice.