Not financial, legal, or tax advice. This guide is for general education only. Stablecoins carry risks, including the risk that a coin loses its peg. Do your own research and consider consulting a qualified professional before relying on them.

Stablecoins are cryptocurrencies designed to hold a steady value, usually pegged one-to-one to a currency like the US dollar. They aim to give you the speed and flexibility of crypto with far less of the price volatility, which makes them a common tool for saving, trading, and moving money on a blockchain.

Table of Contents

What stablecoins are

Most cryptocurrencies swing in price, sometimes violently. That makes them exciting to some investors and impractical for everyday payments or for parking value. Stablecoins were created to solve that problem. A stablecoin is a token, typically issued on a network like Ethereum or Solana, that is engineered to track the value of a stable reference asset, most often the US dollar.

The Bank for International Settlements notes that a stablecoin's peg only holds as long as the reserves behind it do. Because they live on a blockchain, stablecoins move with the same speed and openness as any other cryptocurrency, while aiming to stay close to a familiar value. That blend is why they have become one of the most widely used categories in the whole space.

The scale surprises people who assume crypto is mostly Bitcoin speculation. Stablecoins settle more value on-chain than any other asset class, and a large majority of all crypto trading is denominated in them rather than in dollars. They are the cash layer the rest of the market runs on. Strip them out and most of the ecosystem stops functioning, which is exactly why regulators pay closer attention to them than to almost anything else in crypto.

It is worth being precise about what one actually is, because the name flatters the design. A fiat-backed stablecoin is not digital cash. It is an IOU: a private company's promise that it holds a dollar somewhere and will give it to you on request. The token is only ever as good as that promise and the assets behind it. What you are holding is credit risk on an issuer, wrapped in something that moves like software. That is not a criticism, it is just the accurate description, and it explains every risk in this guide.

The main types of stablecoin

Not all stablecoins keep their value the same way. The main approaches are:

Fiat-backed stablecoins. These are backed by reserves of traditional money and equivalents held by the issuer. For every token in circulation, the issuer aims to hold a matching dollar (or near-cash asset) in reserve. The largest stablecoins today work this way; we compare the two biggest, USDT and USDC, in detail. The three main designs differ sharply in how much you have to trust the issuer.

Crypto-backed stablecoins. These are backed by other cryptocurrencies locked in smart contracts. Because the collateral is itself volatile, these systems usually require more collateral than the value of the stablecoins they issue, providing a buffer against price swings.

Algorithmic stablecoins. These try to hold their peg using rules and market incentives rather than holding full reserves. This category has proven especially fragile, and some high-profile algorithmic stablecoins have collapsed, wiping out holders. Treat them with particular caution.

The trade-off across the three is really a question about what you would rather trust. Fiat-backed coins ask you to trust a company and its auditors, and in exchange give you the most reliable peg. Crypto-backed coins replace that company with code you can inspect, and charge you for it in capital efficiency: locking up 150 dollars of volatile collateral to issue 100 dollars of stablecoin is the price of not needing a bank. Algorithmic designs promised both, needing neither reserves nor a trusted issuer, which should have been the tell.

The reason that promise keeps failing is worth understanding, because someone will make it again. Algorithmic pegs generally rely on arbitrage with a second, floating token: if the stablecoin drifts below a dollar, traders are incentivized to burn it for a dollar's worth of the other token. That works while the second token has value. In a panic, the mechanism prints more of the floating token exactly as everyone is selling it, so its price collapses, so the protocol prints more, faster. The design is stable in calm markets and reflexively self-destructive in the only conditions where stability matters. Our breakdown of the three stablecoin designs covers the mechanics in more depth.

How pegs actually work

A peg is simply the target value a stablecoin tries to maintain, such as one dollar. Keeping that peg depends on the design.

For fiat-backed coins, the promise is that you can always redeem one token for one dollar from the issuer, so the market price stays near a dollar because arbitrage traders profit whenever it drifts. For crypto-backed coins, over-collateralization and automated liquidations defend the peg. For algorithmic coins, the peg relies on incentives that can break down under stress.

The key insight is that a peg is a claim about a mechanism working, not a law of nature. When the mechanism or the trust behind it weakens, a stablecoin can lose its peg, meaning it trades below its target value. This has happened even to large, well-known stablecoins during periods of stress, though the biggest fiat-backed coins have generally recovered.

The arbitrage that holds a fiat-backed peg is worth following once, because it explains why redemption access matters more than reserves. If the token trades at 99 cents and you can redeem it with the issuer for a full dollar, buying it is free money, and enough people doing that pushes the price back to a dollar. Notice the dependency: the mechanism runs on the redemption being real and available. Most retail holders cannot redeem directly at all, since issuers deal with large institutions and minimum sizes. Retail relies on those institutions arbitraging on their behalf. When that channel is doubted or disrupted, the peg is defended by nothing but sentiment.

This is also why reserve composition, not just reserve size, decides whether a peg survives. Full backing by short-term US Treasuries can be liquidated in a day to meet redemptions. Backing by commercial paper, loans to affiliates, or anything illiquid is fine until everyone asks at once, which is the classic bank run and precisely what deposit insurance exists to prevent in the banking system. Stablecoins have no such backstop, which is why the Bank for International Settlements keeps returning to the point.

What people use stablecoins for

Stablecoins serve several practical purposes:

  • A resting place between trades. Investors often move into stablecoins to step out of volatility without leaving the crypto ecosystem entirely.
  • Payments and transfers. They allow fast, low-cost transfers across borders, at any hour.
  • Access to decentralized finance. Stablecoins are heavily used for lending, borrowing, and earning yield across decentralized finance.
  • Saving in a familiar unit. For people in regions with unstable local currencies, dollar-linked stablecoins can be a way to hold value, though they carry their own risks.
  • Payroll and remittances. Paying a contractor overseas settles in seconds for cents, rather than days for a percentage, which is why a growing number of firms do it.

That fourth use is the one that gets least attention in wealthy countries and matters most everywhere else. If your national currency has lost half its value in a year, a dollar-pegged token reachable from any phone is not a trade, it is the only savings account available. The risks in this guide are entirely real, and they are still smaller than the currency being fled. Judging stablecoins purely from somewhere with a stable currency and a working banking system misses most of the point of them.

When pegs break

The theory is easier to trust once you have seen how it actually plays out, and there are two instructive cases.

The algorithmic collapse. In May 2022, TerraUSD, then among the largest stablecoins, lost its peg and went to essentially zero within days, destroying tens of billions of dollars. It worked exactly as the previous section describes: the peg depended on a sister token, confidence broke, the mechanism minted that token into a collapsing market, and the spiral ran to completion in under a week. It had a large market cap, prominent backers, and a well-known founder. None of that mattered, because the mechanism was unsound and a sufficiently bad week was all it ever needed.

The reserve scare. In March 2023, USDC briefly fell to about 87 cents. Nothing was wrong with the code. Its issuer, Circle, held several billion dollars of reserves at Silicon Valley Bank, which failed that weekend, and nobody knew whether that money was recoverable. The US government guaranteed the deposits, the reserves were intact, and the peg restored within days. The design worked, and it still de-pegged for two days, because a fully-backed stablecoin is only as sound as the bank holding the backing.

The lesson from the pair is not that stablecoins fail; it is that they fail for different reasons and to different depths. The first was fatal and structural. The second was temporary and external, and anyone who panic-sold at 87 cents took a real loss on an asset that was fine. Knowing which kind of event you are looking at, in the moment, with incomplete information, is the actual skill. The safest general habit is not to need the answer urgently: the risks worth understanding are specific, and spreading holdings across more than one issuer costs nothing.

Risks to understand

  • Peg risk. A stablecoin can lose its peg and trade below its target, especially under stress or if reserves are questioned.
  • Issuer and reserve risk. For fiat-backed coins, you are trusting that the issuer actually holds sufficient, high-quality reserves and will honor redemptions.
  • Smart contract risk. Stablecoins on a blockchain depend on code that could contain bugs.
  • Regulatory risk. Stablecoins are a focus of regulators worldwide, and rules are evolving.
  • Not a savings account. Holding a stablecoin is not the same as a bank deposit and generally carries no equivalent protection.
  • Freezing and blacklisting. The major fiat-backed issuers can freeze tokens at any address, and have done so at the request of law enforcement. This is a feature for compliance and a limit on the idea that the asset is yours unconditionally.
  • Wrong-network risk. The same stablecoin exists on many blockchains, and they are not interchangeable. Sending on the wrong network is one of the most common ways people lose funds permanently.

The yield question deserves singling out, because it is where most stablecoin losses actually happen. A stablecoin sitting in your own wallet earns nothing; it is a token, not a deposit, and nobody is paying you to hold it. Any advertised return is coming from somewhere, and the somewhere is always someone borrowing, some protocol taking risk, or an issuer sharing interest on reserves. That does not make it illegitimate, but it does mean the question is never whether the yield is good, it is who is paying and what happens to your money when they stop. Double-digit returns on a dollar-pegged asset are not a better savings account; they are an unsecured loan you have not read the terms of. Our guide to earning yield on stablecoins takes the sources apart one by one.

Common misconceptions

"Stablecoins are safe because they are stable." They are stable in price, which is a different property from safe. The risks did not disappear; they moved from market risk to issuer, regulatory and technical risk. A dollar that stays a dollar right up until the issuer fails is not a safe dollar.

"They are backed by cash in a vault." Reserves are typically short-term government debt and similar instruments, held at banks, not physical cash. That is the sensible way to run it, and it also means the reserves have their own counterparty risk, as USDC discovered.

"USDT and USDC are basically the same." Both target a dollar and both are fiat-backed, but they differ in domicile, regulatory posture, and how much detail they publish about reserves. We compare the two directly.

"A stablecoin is like a bank account." There is no deposit insurance, no regulator guaranteeing your balance, and no branch to complain to. If the issuer fails, you are an unsecured creditor.

"Terra proved stablecoins do not work." Terra proved algorithmic stablecoins without real backing do not work, which was predictable and predicted. Fiat-backed coins have absorbed a banking crisis, an issuer scare, and several market collapses without permanently breaking. They are different instruments that shared a name.

"Holding stablecoins is not taxable." Swapping crypto for a stablecoin is a disposal in most jurisdictions, and taxable, even though no ordinary money changed hands. This is one of the most common surprises. See crypto taxes in plain English.

How to get started

If you are new, begin with the basics of how crypto works and how wallets work. When choosing a stablecoin, favor established, transparent, fiat-backed options, and understand who issues them and how they are backed — the risks worth knowing are specific and worth reading before you hold any meaningful amount.