Understanding Stablecoins: How They Work and Where the Risks Are

Most cryptocurrencies are designed to be freely priced by the market, which is exactly what makes them volatile. Stablecoins take a different approach: they are built to track the value of another asset, almost always a major fiat currency like the US dollar, so that one unit stays close to one dollar rather than swinging with the wider market. That single design goal, stability, is achieved through several genuinely different mechanisms, each with its own trade-offs.

What a Stablecoin Actually Is

A stablecoin is a cryptocurrency designed to maintain a peg to a reference asset, most commonly the US dollar. Unlike Bitcoin or Ethereum, a well-functioning stablecoin is not meant to appreciate — its entire purpose is to stay close to a fixed value, giving crypto users a way to hold dollar-like exposure, move value, and trade without leaving the crypto ecosystem or converting back to a traditional bank account each time.

Fiat-Backed Stablecoins

The most widely used stablecoin design holds reserves of real-world assets, typically cash and short-term government debt, roughly equal to the number of tokens in circulation. In principle, each token can be redeemed for its underlying dollar value because that value is sitting in reserve. USDC, issued by Circle, is a well-known example of this model; you can read more on its coin page. The strength of this design is simplicity: the peg is backed by assets a holder could, in theory, trace. Its weak point is trust — you are relying on the issuer to actually hold what it claims, manage those reserves responsibly, and honour redemptions.

Crypto-Collateralised Stablecoins

A different approach backs the stablecoin with other cryptocurrencies rather than cash, locked in smart contracts as collateral. Because crypto collateral is itself volatile, these systems typically require users to lock up more value than they borrow out, known as overcollateralisation, so that the peg can survive a drop in the collateral's price. DAI, associated with the Maker protocol, is the best-known example of this design; see its coin page for more detail. This model trades reserve-transparency risk for a different kind of risk: the collateral's price behaviour and the smart contract logic that manages it.

Algorithmic Stablecoins

A third, more experimental category tries to maintain its peg through code and market incentives rather than holding a reserve of outside assets, for example by algorithmically expanding or contracting supply in response to price. This design removes the need to trust a reserve custodian, but it depends entirely on the incentive mechanism continuing to work as intended, including during periods of market stress. Algorithmic designs have historically proven the most fragile of the three approaches, and it is worth treating any stablecoin without transparent, verifiable backing with particular caution.

Yield-Bearing and Other Newer Designs

Beyond the three core designs, newer variations have emerged that combine features of more than one category, or that pass on yield generated from reserves to holders directly. These hybrid approaches can blur the lines between the categories above, but the same underlying questions still apply: what actually backs the token, how transparent is that backing, and what happens to holders if the mechanism comes under stress. A more complex design is not automatically riskier or safer than a simple one — it simply means there is more detail to verify before relying on it.

Reserves and Transparency

Because the entire value proposition of a fiat-backed stablecoin rests on the claim that reserves exist, transparency practices matter enormously. Look for regular, ideally independent, attestations or audits of reserve composition, clear disclosure of what the reserves actually contain (cash and short-term government debt are generally considered lower-risk than less liquid holdings), and a clear, usable redemption process. An issuer that publishes little detail about its reserves is asking for more trust than one that publishes regularly and in specific terms. Independent attestations are not the same as a full audit, and it is worth understanding which one an issuer is actually providing rather than assuming the two are interchangeable.

Stablecoins and Regulation

Because stablecoins sit close to the traditional financial system, particularly the fiat-backed kind, they have attracted growing regulatory attention in multiple jurisdictions, generally focused on reserve requirements, disclosure standards, and consumer protection. Regulatory frameworks and requirements vary by country and continue to develop, so it is worth checking the current rules that apply in your own jurisdiction rather than assuming a stablecoin is automatically regulated the same way everywhere it is used. A stablecoin issuer operating under clear regulatory oversight in a major jurisdiction is generally providing a different level of accountability than one operating with no such oversight at all.

Depeg Risk

A "depeg" happens when a stablecoin's market price moves meaningfully away from its target, even briefly. Minor, short-lived wobbles of a fraction of a cent are common and usually self-correct as arbitrage traders buy the cheaper side and sell the more expensive side. A more serious depeg, where the price falls well below target and stays there, usually signals a genuine problem with reserves, collateral, or the mechanism itself, rather than ordinary market noise. Our guide on how stablecoins hold their peg explains the arbitrage mechanics and historical stress points in more depth.

A Note on Yield Offers

Because stablecoins are often used as the base currency for earning yield on various platforms, it is worth separating the stablecoin itself from whatever platform is offering a return on it. A well-designed, transparent stablecoin can still be deposited into a poorly run or fraudulent yield platform, and the risks of the two are not the same thing. An unusually high advertised yield on a stablecoin deposit, particularly one significantly above what comparable platforms offer, is a signal to research the platform itself carefully rather than a reason for confidence, since a legitimate platform's yield is ultimately paid from somewhere real.

What Stablecoins Are Actually Used For

In practice, stablecoins are used far more as infrastructure than as an investment. Traders use them to move between positions without exiting to a bank account each time. International users sometimes use them to hold dollar-like exposure where local currency access is difficult. And they serve as the standard unit of account and collateral across much of DeFi, from lending markets to trading pairs. None of these uses eliminate risk — a stablecoin is only as reliable as the mechanism and reserves behind it, whichever of the designs above it happens to use.

This guide is educational and is not financial advice. Holding a stablecoin is not risk-free simply because its price is designed to stay steady; always understand the specific backing mechanism of any stablecoin before relying on it, and do your own research rather than assuming "stable" means "risk-free".

A Simple Framework for Evaluating Any Stablecoin

Before treating any stablecoin as a safe place to park value, ask three questions: What actually backs it, cash, crypto collateral, or an algorithm? How is that backing verified, and how often? And how has its peg held up during the most stressful periods the wider crypto market has been through? A stablecoin that can answer all three clearly is a fundamentally different proposition from one that cannot.