A stablecoin is a token designed to track the value of something stable, most often one US dollar. It keeps that peg in one of three ways: an issuer holds reserves of cash and similar assets and promises to redeem tokens, users lock up more crypto than the stablecoins they create, or an algorithm expands and shrinks supply. None of these is a bank deposit, and each can break in its own way.
"Stable" describes the goal, not a guarantee. To judge a stablecoin you need to know who stands behind the promise, what the reserves are, who can redeem, and who can freeze tokens. That is what this guide explains, without recommending any coin or platform.
Why do stablecoins exist at all?
Most digital assets swing in value by large amounts within a day. That makes them awkward for anything that needs a predictable number: paying an invoice, pricing a contract, or simply parking value between trades. Stablecoins were created to bring a familiar unit, usually the US dollar, onto blockchains so that value can move with the speed and openness of a blockchain without the price swings.
In practice they are used for moving value between platforms, settling trades, and in some countries as a way for people to hold something dollar-like. They are also, unfortunately, a favourite of scammers, because victims understand "one token equals one dollar" and feel safe.
The important mental shift is this: a stablecoin is a promise made by someone, enforced by something. Your job is to find out who made the promise and what enforces it. A bank deposit is backed by regulation and, in many places, deposit insurance. A stablecoin is backed by whatever its design says, and only as well as that design is run.
Three ways to hold a peg, compared
Most stablecoins fall into one of these families. Some mix features of more than one.
| Design | How the peg is held | Typical way it breaks |
|---|---|---|
| Fiat-backed (issuer reserves) | A company holds cash, short-term government debt and similar assets, and redeems tokens for eligible customers | Reserves are smaller or riskier than claimed, a bank holding the reserves fails, or redemptions are frozen |
| Crypto-collateralised | Users lock up more crypto than the value of stablecoins they create; smart contracts sell the collateral if it falls too far | A sharp crash moves faster than liquidations can keep up, or the smart contract has a flaw |
| Algorithmic | Rules mint or burn tokens, often paired with a second token, to push the price back to the peg | Confidence breaks, everyone exits at once, and the mechanism spirals downwards |
| Commodity-backed | Tokens represent a claim on a stored asset such as gold | Storage, audit or redemption problems; the token is only as good as the custodian |
The pattern is clear: the further a design drifts from simple, verifiable, redeemable reserves, the more it relies on everyone continuing to believe in it.
Questions to ask before trusting any stablecoin
Who is the issuer, and where are they regulated? A named company under a known regulator is not a guarantee, but an anonymous team leaves you with no one to hold to account.
What exactly are the reserves? Cash and short-term government debt behave very differently from loans to related companies or other crypto.
Are the reserves audited, or only "attested"? An attestation checks balances at a moment in time. A full audit goes further. Read which one the issuer actually publishes.
Who can redeem tokens for real money? Often only verified institutional customers can redeem directly. Everyone else relies on selling to someone else on a market.
Can the issuer freeze tokens? Many centrally issued stablecoins can freeze addresses, usually to comply with law enforcement. That also means your tokens could be frozen by mistake or in a dispute.
What happened during past stress? Search for how it behaved when markets crashed or a partner bank struggled. A brief slip that recovered tells you something different from a collapse.
Which blockchain version are you holding? The same stablecoin may exist on several networks. Sending it on the wrong network is one of the most common ways people lose funds.
What is the legal status where you live? Rules in Vietnam on digital assets are still evolving. Check current official guidance or ask a lawyer rather than relying on what a platform says.
What a "depeg" looks like from the inside
A depeg rarely starts with the price. It usually starts with a rumour: a reserve bank in trouble, a large holder redeeming, a smart contract bug, a regulator asking questions. Traders who move fastest sell first, the price slips slightly below one dollar, and that slip itself becomes news that pushes more people to sell.
For fiat-backed coins with solid reserves, arbitrage often pulls the price back: someone who can redeem at one dollar buys cheap tokens on the market and redeems them. That mechanism only works if redemption stays open and the reserves are what was promised. When those conditions hold, slips tend to be brief. When they do not, the slide can become permanent.
For algorithmic designs, the story can be much worse. The mechanism that is supposed to restore the peg may require minting huge amounts of a sister token, which crashes its price, which weakens the peg further. There has been at least one widely reported case where a large algorithmic stablecoin lost almost all its value within days.
For an ordinary holder, the practical lesson is to avoid treating any stablecoin as a savings account, to be suspicious of platforms promising fixed high returns on stablecoins, and to keep in mind that "redeemable" usually means redeemable by someone else, not you.
Common stablecoin mistakes
Treating "stable" as "safe". Price stability is one property. Counterparty risk, platform risk and scam risk are separate, and all still apply.
Chasing fixed yields on stablecoins. High, steady returns have to come from somewhere, usually lending to borrowers you cannot see. When the borrowers fail, the "stable" deposit is gone.
Sending on the wrong network. A token on one blockchain is not automatically visible on another. Always match the network the recipient specifies, and test with a small amount.
Copying an address from chat history. Address-poisoning scams plant look-alike addresses in your history. Copy from the source each time and compare the full string.
Assuming a platform's internal balance is the real token. On an exchange you hold a claim on the exchange, not the token itself. If the platform freezes withdrawals, the peg of the coin does not help you.
Ignoring freeze powers. If you receive tokens from a disputed or criminal source, they may be frozen in your wallet. Know who you trade with.
Assuming a legal guarantee exists. Stablecoins are not covered by deposit insurance in most places. Losses are usually yours to carry.
Frequently asked questions
Is a stablecoin the same as a digital dong or a central bank digital currency?
No. A central bank digital currency would be issued by the central bank itself, while stablecoins are issued by private companies or protocols.
Can a stablecoin go to zero?
Yes. If reserves are missing, the mechanism fails or confidence collapses, a stablecoin can lose most or all of its value, and this has happened.
Why can my stablecoins be frozen if I did nothing wrong?
Centrally issued stablecoins usually include a freeze function, used when funds are linked to theft or a legal order. Tokens received from a tainted source can be caught up in this.
Are stablecoin "savings" products safe?
They are not bank savings and are usually not insured. The yield comes from lending or other risky activity, and several such platforms have frozen withdrawals in the past.
Are stablecoins legal in Vietnam?
The legal framework for digital assets in Vietnam is changing, so any short answer may be out of date. Check current official documents or ask a lawyer before using them for business.
