How Do Stablecoins Like USDT Actually Work?

Stablecoins like USDT (Tether) and USDC are the quiet workhorses of the crypto world. While Bitcoin grabs headlines with wild price swings, stablecoins do something radical by crypto standards: they stay at roughly one dollar. Billions of dollars’ worth change hands daily — traders park profits in them, people in unstable economies use them as dollar substitutes, and entire DeFi markets run on them. But how does a cryptocurrency actually hold its value steady? And how safe are they, really?

Understanding stablecoins means understanding the machinery underneath the $1 peg — the reserves, the redemption promises, and the risks that have blown up more than one “stable” coin. Here’s the full picture for Americans trying to make sense of them in 2026.

The basic idea: a crypto dollar

A stablecoin is a cryptocurrency designed to maintain a stable value, usually pegged 1:1 to the US dollar. One USDT or USDC is meant to always be worth about $1.00. This makes them useful in ways volatile crypto isn’t: you can move dollars across borders in minutes, trade in and out of crypto positions without touching a bank, or earn yield without riding Bitcoin’s roller coaster.

Think of it this way: Bitcoin is like a volatile stock, while a dollar-pegged stablecoin is meant to function like a digital dollar bill. The stability is the entire point — and the entire engineering challenge.

How the peg actually works: three designs

Not all stablecoins hold their peg the same way. There are three main designs, and the differences matter enormously for safety.

1. Fiat-backed (USDT, USDC) — the most common

Fiat-backed stablecoins are the simplest conceptually: the issuer holds real-world reserves (dollars, Treasury bills, and similar assets) and issues one token per dollar of reserves. You should be able to redeem 1 USDT for $1 from the issuer. The peg holds because of arbitrage: if USDT trades at $0.99 on an exchange, traders buy it cheap and redeem it for $1.00, pocketing the difference — and their buying pushes the price back up. If it trades at $1.01, they mint new tokens and sell them.

The entire system rests on one question: are the reserves really there? USDC’s issuer, Circle, publishes regular attestations of its reserves and keeps them in cash and short-term US Treasuries. Tether (USDT), the largest stablecoin, has faced years of scrutiny over its reserve disclosures — it paid a $41 million fine to the CFTC in 2021 over misleading claims about its backing. The reserves question is why regulators and analysts obsess over attestations and audits.

2. Crypto-backed (DAI) — overcollateralized by crypto

DAI, issued by the MakerDAO protocol, is backed not by dollars in a bank but by other cryptocurrencies locked in smart contracts. To mint $100 of DAI, you might lock up $150+ worth of Ethereum as collateral. If the collateral’s value falls too far, the system automatically liquidates it. The overcollateralization buffer is what keeps DAI near $1 even when crypto markets crash. It’s decentralized — no single company holds the reserves — but more complex and historically more volatile around the edges.

3. Algorithmic — the design that blew up

Algorithmic stablecoins tried to hold the peg with code alone — no real reserves, just algorithms that expanded or contracted supply. The catastrophic collapse of TerraUSD (UST) in May 2022, which wiped out roughly $40 billion in days, proved how fragile this design is. When confidence broke, the algorithm’s death spiral took the peg to zero. The lesson: avoid algorithmic stablecoins. The market learned this the hard way.

What Americans actually use stablecoins for

• Trading: moving in and out of volatile crypto positions without the delays and fees of bank transfers. This is the dominant use.
• Transfers: sending dollars internationally in minutes for fractions of a cent, versus wire fees and multi-day waits.
• Savings and yield: some platforms pay interest on stablecoin deposits — but treat advertised yields with deep skepticism (more below).
• Dollar access abroad: in countries with unstable currencies, dollar stablecoins function as accessible dollar savings.

For most Americans, the honest use cases are trading and transfers. If you’re just looking to manage your personal finances or save for a big purchase, a high-yield savings account is simpler and FDIC-insured.

The risks nobody advertises

They’re not FDIC-insured

This is the big one. Dollars in a US bank are FDIC-insured up to $250,000. Stablecoins are not deposits, not insured, and not guaranteed by anyone. If the issuer fails or the peg breaks, you can lose money — full stop. Regulators including the SEC have been circling stablecoins for years, and the regulatory picture is still evolving.

De-pegging happens

Even major stablecoins wobble. USDC briefly fell to around $0.87 in March 2023 when its issuer had deposits stuck at the failed Silicon Valley Bank. It recovered — but the episode proved the peg is a market outcome, not a law of physics. Smaller stablecoins have de-pegged far worse.

Counterparty and platform risk

Billions in customer funds were lost when crypto lenders like Celsius and BlockFi collapsed in 2022 — many customers had deposited stablecoins chasing yield. The stablecoin itself didn’t fail; the platform holding it did. Where you keep stablecoins matters as much as which one you hold. The Consumer Financial Protection Bureau has warned consumers about crypto asset risks generally.

Regulatory risk

Stablecoin regulation in the US has been debated for years, with proposals ranging from requiring issuers to be insured banks to mandating specific reserve standards. Future rules could change how stablecoins work or which ones Americans can use. The SEC’s investor education site is worth reading before putting significant money into any crypto product.

USDT vs. USDC: the practical comparison

• USDT (Tether): largest by market cap, most widely accepted, most trading pairs. But its reserve transparency has historically been weaker, and it’s faced regulatory penalties.
• USDC (Circle): generally considered more transparent — regular attestations, reserves in cash and Treasuries, US-based issuer. Slightly less ubiquitous than USDT in some markets.

Neither is risk-free. If you use stablecoins, prefer the most transparent large issuers, keep amounts modest relative to your savings, and never treat them as equivalent to bank deposits.

Stablecoins and taxes: yes, they count

The IRS treats cryptocurrency — including stablecoins — as property, not currency. Trading, spending, or converting stablecoins can create taxable events, and interest earned is taxable income. Stable-to-stable trades and even small transactions technically count. If you’re active, read our guide on handling taxes on self-directed income and consider proper tracking from day one. For business banking context, see choosing a business bank account.

The bottom line

Stablecoins like USDT work through a simple-sounding promise — one token, one dollar of reserves, redeemable on demand — held together by arbitrage and, critically, trust in the issuer’s reserves. The mechanism is clever, the use cases for trading and transfers are real, and the largest fiat-backed coins have survived serious stress tests. But they’re not dollars, they’re not insured, and the Terra collapse proved that “stable” is a design goal, not a guarantee. Use them as tools for specific jobs, in amounts you can afford to have frozen or impaired — never as your savings account.

Frequently Asked Questions

Is USDT actually backed by real dollars?

Tether claims its tokens are fully backed by reserves including cash, Treasury bills, and other assets, and now publishes regular attestations. But it has a history of opacity and paid a CFTC fine in 2021 over past claims. USDC’s disclosures are generally considered more transparent.

Can a stablecoin lose its $1 peg?

Yes. USDC briefly dropped to ~$0.87 in March 2023 during the Silicon Valley Bank crisis, and TerraUSD collapsed to near zero in 2022. The peg is maintained by markets and reserves, not guaranteed.

Are stablecoins FDIC insured?

No. Stablecoins are not bank deposits and carry no FDIC insurance. If the issuer fails, there is no government backstop for your funds.

What’s the difference between USDT and USDC?

Both are dollar-pegged and fiat-backed, but they have different issuers (Tether vs. Circle), different transparency practices, and different regulatory histories. USDC is generally viewed as more transparent; USDT is more widely used in trading.

Do I owe taxes on stablecoin transactions?

Generally yes. The IRS treats crypto as property, so trades, conversions, and interest can all be taxable events — even when the price barely moves from $1.