Explainer · Stablecoins
What is a stablecoin?
September 21, 2026
Stablecoins move more transaction value than almost anything else in crypto — they are the most-used product this industry has actually built. Yet the word "stablecoin" covers three very different designs, each with a different answer to what happens if the peg is ever tested. Here is what actually backs each kind, why one of them has a particularly rough track record, and what to check before trusting any of them with real money.
What actually makes something a stablecoin
A stablecoin is a token engineered to hold a steady price — almost always one U.S. dollar. That stability is not automatic. It is a promise, backed by some underlying mechanism, and the mechanism is the entire story of any given stablecoin.
There are three broad ways to build one: hold real dollars in reserve, hold crypto collateral in a smart contract, or try to hold the peg through market mechanics alone, with no hard collateral behind it at all. Which model a stablecoin uses determines what can actually go wrong with it — and how a holder would know before it does.
The three backing models
- Fiat-backed. For every token issued, the issuer holds a dollar — or a dollar-equivalent asset, like short-term Treasuries — in reserve. This is the simplest model and by far the largest category. The real question isn't the mechanism; it's trust: does the issuer actually hold what it claims, is that backing audited or merely attested, and can a holder redeem the token for a real dollar on demand?
- Crypto-backed, overcollateralized. Instead of trusting an issuer's bank account, a holder locks crypto — usually worth more than the stablecoin being minted, to absorb price swings — into a smart contract, which mints the stablecoin against that collateral. The reserve is on-chain and verifiable by anyone, no bank statement required. The tradeoff is exposure to the collateral's own volatility: if it falls fast enough, the system has to liquidate positions to stay solvent.
- Algorithmic. This model tries to skip collateral almost entirely, holding the peg through supply-and-demand mechanics and market incentives — sometimes paired with a second, volatile token that absorbs the swings. It is the most capital-efficient design on paper, and the least proven under pressure.
Why algorithmic stablecoins have a rough track record
The appeal of an algorithmic design is real: fully decentralized, capital-efficient, no reserve to trust. So is the problem. Several prominent algorithmic stablecoins have de-pegged and collapsed, because the mechanism depends on confidence holding up under stress — and in a panic, confidence is exactly what breaks first.
That doesn't make the idea fake. It means the design has a much higher bar to clear to survive a real crisis, and its track record against that bar so far is poor. A stablecoin that has never been tested by a genuine stress event hasn't actually proven its peg holds — it has simply never been asked to.
What to actually check
Before trusting any stablecoin with real money, three questions do most of the work. What actually backs it — cash and Treasuries, crypto collateral, or nothing but a mechanism? Is that backing disclosed and verifiable, or just asserted by the issuer? And has it been tested by a real market stress event, not just a calm one?
None of those questions require special expertise to ask. They just require asking them before the money moves, rather than after the peg breaks.
The read
Stablecoins are the part of crypto that already works at scale — the plumbing that moves value in and out of every other asset in this industry. But "stable" is a promise, not a guarantee, and the mechanism behind that promise is exactly what determines whether it holds when it matters. A fiat-backed stablecoin is itself a tokenized real-world asset — a claim on dollars held somewhere else — which is why it belongs in the same conversation as tokenized Treasuries and other RWAs.
This is general-circulation educational content, not investment or legal advice. Stablecoins carry issuer, collateral and mechanism risk; a stable price today does not guarantee one tomorrow.
For what's backing tokenized dollars and other real-world assets today, see Blockchain IQ's report The Real World — RWAs.