What a stablecoin is

A stablecoin is a cryptocurrency designed to hold a steady value, almost always pegged to one US dollar. Ordinary crypto like Bitcoin can swing wildly in a day, which makes it awkward for payments or for parking money. A stablecoin tries to combine the speed and programmability of crypto with the steadiness of a traditional currency, so one coin is meant to be worth about one dollar at all times.

How the peg is supposed to hold

The most common and most trusted design is full backing by reserves. For every coin in circulation, the issuer holds a dollar, or a safe dollar-equivalent such as short-term US government debt, that can in principle be redeemed. If the coin ever trades below a dollar, buyers can profit by redeeming it for the full dollar of reserves, which pushes the price back up. The soundness of such a coin depends entirely on whether the reserves are real, liquid and fully covering the coins, which is why reserve disclosures and audits matter so much.

A riskier design is the algorithmic stablecoin, which tries to hold its peg not with cash reserves but with code and a linked token that absorbs the swings. These have a poor record.

What they are used for

Stablecoins are mainly plumbing. Traders use them to move in and out of crypto positions without converting back to a bank account each time. People use them to send money across borders quickly and cheaply. And they are increasingly used for payments and settlement, because a dollar-pegged token can move in minutes at any hour. For the wider world of finance-as-software they sit inside, see what is fintech.

Why stable does not mean safe

The word stable describes a goal, not a guarantee. A stablecoin can lose its peg, which the market calls depegging, if its reserves turn out to be insufficient, if too many holders try to redeem at once, or if confidence simply breaks. The most dramatic example came in 2022, when a large algorithmic stablecoin collapsed to near zero in days, wiping out tens of billions of dollars. Even reserve-backed coins have wobbled when doubts spread about what was actually backing them.

Why regulators are watching

Stablecoins have grown large enough that governments now treat them as financial infrastructure, not a crypto curiosity. The worry is twofold: that a big coin could lose its peg and spread trouble, much as a run on a money-market fund can, and that holders assume a safety that is not really there. The direction of travel in several countries is toward rules on what reserves a stablecoin must hold and who may issue one, aimed at making the word stable mean something closer to what users expect.

Crucially, stablecoins are not bank deposits. They are not covered by FDIC insurance, and the protection you get depends on the issuer, the rules it follows and the honesty of its reserves.

What to look at before trusting one

• What backs it? Cash and short-term government debt are very different from riskier assets or an algorithm.
• Who proves it? Regular, independent reports on the reserves, not just the issuer's word.
• Who issues it, and under what rules? A regulated issuer is more accountable than an anonymous one.

The bottom line

A stablecoin is a crypto token built to stay at about a dollar by being backed, ideally, by real reserves. At its best it is fast, cheap digital cash; at its worst it is a promise that breaks. The single most useful habit is to look past the word stable and ask what actually stands behind the coin. The glossary defines the terms.