What is a stablecoin

A stablecoin is a type of cryptocurrency engineered to keep a stable value, almost always by tracking a real-world asset such as the US dollar at a 1-to-1 rate. The idea is to combine the speed and programmability of crypto with the price stability of regular money, so one unit is meant to stay worth about $1 instead of swinging wildly like Bitcoin. The biggest examples are Tether (USDT) and USD Coin (USDC).

It depends on the type. The dominant model is fiat-backed: a company holds reserves (cash and short-term US Treasuries) and issues one token for every dollar held, so the token can in theory be redeemed for a real dollar. Crypto-collateralized stablecoins like DAI lock up other crypto (such as Ether) as over-sized collateral. A third, now largely discredited model, algorithmic stablecoins, used software rules and a paired token to manage supply with no real reserves behind them.

People use stablecoins to trade in and out of crypto without converting back to a bank account, to send money across borders quickly and cheaply, to earn yield in decentralized finance (DeFi) apps, and as a place to park value during volatile markets. Increasingly they are also used for everyday payments and business settlements. They act as the dollar 'cash layer' of the crypto economy.

There are three main types. Fiat-collateralized (USDT, USDC) are backed by reserves of cash and government bonds. Crypto-collateralized (DAI) are backed by other cryptocurrencies held as over-collateral. Algorithmic stablecoins tried to hold their peg purely through supply-and-demand software mechanics with little or no collateral. The first two dominate today; the algorithmic model lost most of its credibility after the 2022 Terra/UST collapse.

A fiat-backed stablecoin is supported by real reserves: for every token in circulation, the issuer claims to hold roughly one dollar of cash or safe bonds you could redeem. An algorithmic stablecoin holds no such reserves; it relies on code, market incentives, and a companion token to keep the price near $1. That difference is critical, because when confidence falters, a fiat-backed coin has assets to fall back on while an algorithmic one can enter a 'death spiral,' which is exactly what destroyed TerraUSD in 2022.

Tether (USDT) is by far the largest, with a market value of roughly $188 billion in June 2026 and a market share of close to 58% of all stablecoins. Circle's USD Coin (USDC) is second at around $78 billion. Together those two make up about 92% of the entire stablecoin market, so the sector is highly concentrated in two issuers.

Both are dollar-pegged, fiat-backed stablecoins, but they are run by different companies with different reputations for transparency. USDT, issued by Tether, is the largest and most widely traded but has faced years of questions about exactly what backs its reserves. USDC, issued by Circle, is smaller but is generally seen as more transparent and regulator-friendly, publishing regular reserve attestations. Choosing between them is a question of trust, liquidity, and where you plan to use them.

USDT is the most-used stablecoin and has held its peg through several market shocks, but 'safe' is relative. Tether has long faced scrutiny over the makeup and auditing of its reserves, and it is not bank-insured. It is generally far less volatile than Bitcoin, yet it still carries issuer risk and depeg risk. Treat any single number or claim here as a starting point and check Tether's own published reserve reports, and remember this is context, not financial advice.

Stablecoins are designed to be far more stable than other crypto, and the largest fiat-backed ones usually hold their peg. But 'stable' is not the same as 'risk-free.' The main risks are: the issuer's reserves may not fully cover the tokens, the coin can temporarily lose its peg in a panic, the issuer could face legal or solvency problems, and most are not covered by government deposit insurance. Use them with the same caution you would any financial product, and never assume a guaranteed dollar.

Yes. A 'depeg' is when a stablecoin trades away from its intended value, for example below $1. It can happen in a panic, during a liquidity crunch, or if people doubt the reserves. A well-known case is USDC briefly falling to around $0.87 in March 2023 when part of Circle's cash was stuck at the failing Silicon Valley Bank; it recovered within days. The far more severe case was TerraUSD, which depegged and never recovered.

TerraUSD (UST) was a large algorithmic stablecoin that collapsed in May 2022. It had no real cash reserves and relied on a sister token, LUNA, plus a high-yield program offering around 19.5% to attract deposits. When confidence cracked on 9 May 2022, UST lost its dollar peg, the mechanism minted huge amounts of LUNA, and both spiraled toward zero. Roughly $50 billion in UST/LUNA value was wiped out, and the shock helped trigger around $400 billion in losses across the wider crypto market.

DAI is a stablecoin pegged to the US dollar but backed by cryptocurrency rather than bank dollars. It is created through MakerDAO, where users lock up crypto such as Ether as over-collateral (often 150% or more of the DAI they mint) inside smart-contract 'vaults.' If the collateral's value falls too far, the system automatically liquidates it to keep DAI solvent. Unlike USDT or USDC it is decentralized and governed by holders of the MKR token, not a single company.

Increasingly, yes. The United States passed its first federal stablecoin law, the GENIUS Act, in July 2025, and the European Union's MiCA rules have applied to stablecoins since 2024. Both frameworks generally require full reserve backing, public disclosures, and licensed issuers. Outside these regions the picture varies widely, so the rules that apply to you depend on where you live and where the issuer is based.

The GENIUS Act is the first US federal law for payment stablecoins, signed by President Trump in July 2025. It limits issuance to licensed 'permitted payment stablecoin issuers,' requires 100% reserve backing with cash and short-term US Treasuries, mandates monthly public disclosures of those reserves, applies anti-money-laundering rules, and gives stablecoin holders priority if an issuer goes bankrupt. A separate House bill, the STABLE Act, covered similar ground, but GENIUS is the version that became law.

Yes, under the EU's Markets in Crypto-Assets (MiCA) regulation, whose stablecoin rules have applied since 2024. MiCA treats most dollar- and euro-pegged stablecoins as 'e-money tokens,' which must be issued by an authorized bank or e-money institution, hold 1-to-1 liquid reserves, and meet strict disclosure rules. Crucially, MiCA effectively bans purely algorithmic stablecoins that have no real reserves, which is why the Terra-style model is not viable in the EU.

As of 2026 the total stablecoin market is worth roughly $320 billion, having crossed $310-321 billion through the first half of the year. It has grown steadily, driven by institutional adoption and clearer regulation following the GENIUS Act. The market remains heavily concentrated, with Tether (USDT) and Circle (USDC) together accounting for around 92% of the total.

By design, a stablecoin is not meant to go up in value, so it is not an investment that delivers gains the way a stock or Bitcoin might. People sometimes earn yield by lending stablecoins in DeFi, but that yield carries real risks, including smart-contract failures and depegs, and is not a guaranteed or insured return. Whether holding or lending stablecoins fits your situation is a personal financial decision best discussed with a qualified adviser, not settled by a trending explainer.