Stablecoins, Explained: The Peg, What Breaks It, and Why It Is Not a Savings Account
By the Stoia team · September 12, 2026 · 7 min read
A stablecoin is a cryptocurrency designed to hold a fixed value, almost always one U.S. dollar per token, by backing each token with something (dollars in a bank, short-term government bills, excess crypto collateral) or with an algorithm that adjusts supply. What holds the peg is the credibility of that backing and the ability to redeem a token for a dollar on demand. What breaks it is doubt about either. And whatever the design, a stablecoin is not a savings account: no deposit insurance stands behind it, the issuer can fail, and the price can trade below a dollar exactly when you need it not to.
What a stablecoin is, and what it is for
Crypto markets run around the clock, and moving in and out of dollars through a bank takes days. A stablecoin solves that by putting a dollar-denominated token on the same rails as everything else: you can sell Bitcoin into a dollar-pegged stablecoin in seconds, hold the dollar exposure on the exchange or in a self-custody wallet, and buy back in later, all without a wire. That is the core use, and most of the others (paying someone overseas in dollars, settling between exchanges, denominating a loan in dollars inside a lending protocol) are variations on it. The token is a claim, or a mechanism, that is supposed to be worth a dollar. It is not a dollar.
The three designs: what backs each one
Three families exist, and the one you are holding decides what can go wrong.
| Design | What backs each token | How it redeems | Historical failure mode |
|---|---|---|---|
| Fiat-reserve backed | Dollars, bank deposits, and short-term government securities held by the issuer, meant to equal the tokens outstanding | The issuer or an authorized partner exchanges tokens for dollars, subject to its terms, minimums, and hours | Reserves turn out to be lower quality or less liquid than claimed, or a bank holding them fails; the token trades below $1 until redemptions clear |
| Crypto-overcollateralized | Other crypto locked in a smart contract, worth more than the tokens issued (for example, $150 of collateral per $100 of tokens) | Repay the tokens to unlock the collateral, or the contract sells collateral to cover them | Collateral falls faster than the contract can liquidate it, leaving tokens backed by less than $1 |
| Algorithmic | Nothing directly; a paired token and a supply rule that expands or contracts to push the price back toward $1 | Swap for the paired token at a fixed rate, which is only worth something while confidence holds | A price drop triggers minting of the paired token, its price collapses, and the loop runs to zero |
Fiat-backed tokens dominate by size, and the questions to ask an issuer are the ones you would ask a money market fund: what is in the reserve, who audits it, how often is the report published, and how fast can a holder redeem. Overcollateralized tokens replace issuer trust with code and excess collateral, at the cost of complexity. Algorithmic tokens have the cleanest story and the worst record.
What a peg is, and what "depeg" means
The peg is the target price: one token equals one dollar. It is enforced by arbitrage. If the token trades at $0.99 on an exchange and the issuer will redeem it for $1.00, someone buys at $0.99, redeems at $1.00, and keeps the penny; enough of that and the price is back at $1.00. If the token trades at $1.01, the reverse happens: someone deposits a dollar, mints a new token, and sells it for $1.01. The peg holds as long as redemption is fast, cheap, and believed.
A depeg is what happens when it stops being believed. Illustration: a rumor spreads that an issuer's reserves are partly stuck at a troubled bank. Holders sell on exchanges rather than wait for redemption, and the price drops to $0.94. Arbitrageurs step in only if they are confident they can redeem at $1.00; if the issuer pauses redemptions or takes days, they do not, and the price stays down. If the reserves really are there and become available, the price climbs back over hours or days. If they are not, it does not. The mechanics are the same for a $0.94 dip that recovers and for a collapse; the difference is only what was actually in the vault. A token that has depegged once and recovered is not therefore safe; it has shown you the size of the door people run for.
How a stablecoin differs from a bank deposit
Four differences, each of which answers "are stablecoins safe" in a different way.
- No deposit insurance. A bank account carries FDIC insurance (or the credit union equivalent) up to the federal limit per depositor, per institution, per ownership category. A stablecoin carries none. If the issuer fails, you are a creditor in an insolvency, not a covered depositor, even if the issuer's reserves sat in an insured bank.
- Issuer risk. The token is worth what the issuer's reserves and honesty make it. A bank is examined and backstopped; a stablecoin issuer's obligations depend on its charter, its terms of service, and the regulation it falls under.
- Redemption terms. Your bank must give you your money. An issuer redeems under its own terms: minimum amounts, verified accounts, business days, and a right to pause. Most holders never redeem directly; they sell on an exchange at whatever the market price is that hour.
- Federal rules, as of 2025. Federal legislation enacted in 2025 created a framework for U.S. payment stablecoin issuers: regulated issuers must hold full reserves in cash and short-term government securities, publish regular reserve reports, and give token holders priority over other creditors if the issuer fails. The same rules bar regulated issuers from paying interest on the token itself. This is a real improvement in the fiat-backed category. It does not cover tokens from unregulated or offshore issuers, it does not cover crypto-collateralized or algorithmic designs, and it is not deposit insurance. Because implementation is still rolling out, check the issuer's current disclosures rather than assuming coverage.
The plainest comparison: a high-yield savings account is an insured deposit that pays interest. A stablecoin is an uninsured token that pays nothing by itself. The high-yield savings guide covers the first; the next section covers why the second sometimes appears to pay more.
Where stablecoin yield comes from
Since a regulated issuer cannot pay interest on the token, any yield offered on a stablecoin balance is coming from a platform, and the platform is doing one of four things with your tokens:
- Lending them to borrowers, typically traders who want leverage, and passing along part of the interest. Your risk is the borrower's default and the platform's ability to make you whole.
- Depositing them in a lending protocol, where the rate floats with demand for borrowing. Your risk is a flaw in the code and the collateral behind the loans.
- Passing through reserve income from the government bills the tokens are backed by, in the form of rewards or points rather than interest on the token. Your risk is the platform's solvency and its right to change the program.
- Paying you in its own token as an incentive. Your risk is that the incentive token is worth less than advertised, often quickly.
Worked: $10,000 in a high-yield savings account at 4% earns $400 a year, insured, withdrawable today. The same $10,000 on a platform offering 7% on a stablecoin earns $700. The extra $300 is the price the platform is paying you to take counterparty, code, and depeg risk on the full $10,000. That can be a fair trade for money you can afford to lose; it is a bad trade for money you cannot. The HYSA calculator shows what the insured version compounds to over the years you actually plan to hold it.
Taxes: a stablecoin is still property
The IRS treats every cryptocurrency as property, and a dollar peg does not change that. Selling Bitcoin into a stablecoin is a disposal of the Bitcoin at fair market value: if the Bitcoin cost $4,000 and you swap it for $6,000 worth of stablecoin, you have a $2,000 capital gain the moment the swap settles, even though no dollars ever reached your bank. The stablecoin lot then has a $6,000 basis. When you later swap it back, or sell it for actual dollars, that is another disposal, usually with a gain or loss of a few cents per token as the price wobbles around $1.00, which is still reportable. Yield paid on a stablecoin balance is ordinary income at its dollar value when received. The crypto taxes basics guide covers the full set of events; the point here is that "I only moved into stablecoins" is not a tax-free move.
What stablecoins are good for, and what they are not
Good for: holding dollar exposure between crypto positions without leaving the exchange; moving value between platforms faster than a bank transfer; denominating a payment in dollars where a bank rail is slow or unavailable. In each case the money is already inside crypto, the holding period is short, and the amount is one you could survive losing.
Not for: the emergency fund, which has to be insured, instantly available, and immune to a platform pausing withdrawals on the worst week of your life. Not for rent money, a tax payment, or anything with a date and a payee. Not for a yield play with savings you are counting on, no matter how boring the token looks. The test is simple: if losing 6% of it for a month, or all of it for good, would change a plan, it belongs in a bank. The rest of the crypto basics collection covers sizing a crypto position and keeping the records that make the taxes tractable.
Whatever share of your dollars sits in a stablecoin should show up next to the dollars that sit in a bank, at its actual market price rather than the dollar it is supposed to be. Stoia keeps crypto balances, bank accounts, and brokerage holdings in one live net worth picture, launching 2026.
Frequently asked questions
Are stablecoins safe?
Safer than volatile crypto, less safe than an insured bank deposit. A fiat-backed stablecoin from a regulated issuer holds full reserves and can usually be redeemed at $1, but it carries issuer risk, redemption terms, and no deposit insurance, and it can trade below $1 during a loss of confidence. Crypto-collateralized and algorithmic designs carry more risk than that.
Are stablecoins FDIC insured?
No. FDIC insurance covers deposits at insured banks, not tokens issued by a stablecoin company, even when that company keeps its reserves at an insured bank. If the issuer fails, you are a creditor of the issuer, not an insured depositor.
How do stablecoin issuers make money?
Fiat-backed issuers invest the reserves in short-term government securities and keep the interest. Under the 2025 federal rules, regulated issuers cannot pay that interest to token holders for simply holding the token, so any yield you are offered comes from a platform lending or deploying your tokens, with the platform's own risks attached.
Is swapping crypto into a stablecoin a taxable event?
Yes. A stablecoin is property for tax purposes, so trading Bitcoin or any other coin into a stablecoin is a disposal that realizes a capital gain or loss on the coin you gave up, even though you did not receive dollars. Yield earned on a stablecoin balance is ordinary income at its dollar value when received.
What does it mean when a stablecoin depegs?
A depeg is when a stablecoin's market price moves away from its $1 target, usually downward, because holders doubt they can redeem it at full value. It recovers if redemptions are honored quickly and the reserves are real; it does not recover if the backing was insufficient or the design depends on confidence that has already gone.