What Is USDT? Tether Explained

Open the trading screen on almost any crypto exchange and look at what actually changes hands: not bitcoin against dollars, but bitcoin against USDT, ether against USDT, nearly everything against USDT. Tether's dollar token is the plumbing of the crypto market, and plenty of people end up holding some before they have read a single word about it.

This is an explainer, not financial advice: USDT carries real risks, and nothing below makes them disappear.

A dollar token, not a dollar

USDT is a stablecoin: a crypto token built to track one US dollar. The company behind it, Tether, sells tokens for dollars, parks the money in reserves, and promises to buy tokens back at a dollar each. That issue-and-redeem loop is the whole machine, nothing cleverer than that.

The scale is the striking part: USDT is the largest stablecoin, and circulation passed $100 billion in May 2024. Traders use it as a parking spot between trades, people in countries with wobbly currencies hold it as a pocket dollar, and exchanges quote nearly everything against it because that is where the liquidity sits.

One thing it is not: a bank deposit. No deposit insurance stands behind USDT anywhere, and what you hold is a claim on a private company's reserves, a token only ever as sound as that claim.

From Realcoin to everywhere

Tether is old by crypto standards, launched in July 2014 as Realcoin, riding on Bitcoin's Omni layer, and it took the Tether name soon after. For years it stayed a traders' tool, handy for moving value between exchanges that struggled to hold actual bank dollars.

It stopped being niche: the same token now runs on several blockchains, and most of the supply sits on Tron and Ethereum. Same USDT, different rails. That sounds like trivia, but it is the most practical fact in this article, and it gets its own section below.

How the peg holds, and the day it wobbled

The peg is not magic, and it is not code: it is arbitrage resting on a redemption promise. If USDT trades at 99 cents, traders can buy it and redeem with Tether at a dollar each, pocketing the difference, and that buying drags the price back up. The loop only works while people believe the reserves are real and redemptions actually clear.

Belief got tested on 12 May 2022, when TerraUSD, an algorithmic stablecoin with no reserves behind it, was collapsing and panic spread to anything with 'stable' in the name. USDT dipped to about $0.95, then traded back near $1 within days as redemptions went through. TerraUSD never came back at all.

One week put the two designs side by side: the reserve-backed token bent, the algorithmic one snapped, and that contrast tells you more than any whitepaper.

The record, warts included

Promoters tend to skip this section, and you should not.

In February 2021, Tether settled with the New York Attorney General for $18.5 million over past statements about its reserves. It admitted no wrongdoing and was barred from doing business in New York. In October 2021, the US regulator CFTC fined Tether $41 million over reserve statements made between 2016 and 2018. These are settled matters, not rumours, and they are why 'fully backed' tends to be said with one eyebrow up.

These days Tether publishes quarterly reserve attestations: an accounting firm confirms what the reserves held on one given day. An attestation is not a full audit: it is a photograph, not a film. Plenty of people are comfortable with that arrangement, but you should at least know it is the arrangement before you park real money in it.

One token, several networks

USDT on Ethereum is an ERC-20 token, USDT on Tron is TRC-20. Same dollar claim, entirely different networks, and the addresses look nothing alike: an Ethereum address runs 42 characters starting 0x, and a Tron address starts with T. Transfer fees differ between networks too, sometimes by enough to matter on small amounts.

Every time you send or withdraw USDT, the platform asks which network. Beginners breeze past that screen, and it is the screen that costs money, because coins sent on the wrong network can be gone for good. Slow down there, every single time.

Counterfeits are the other trap: anyone can mint a token called USDT on a cheap chain for pennies, and scammers do, then hand the fakes out as 'payments'. The name proves nothing. What matters is the genuine contract on a network Tether actually issues on, which is one more reason to buy through an established platform rather than accept tokens from a stranger.

Where you can buy it, and what to check first

Availability is genuinely uneven: in the European Economic Area, many platforms restricted USDT for retail customers in early 2025 under MiCA, the EU's crypto-assets rules, so what shows up in your app depends on where you live. In plenty of other markets it is among the most widely offered tokens going, so check what your platform currently lists rather than assuming.

The purchase itself runs like any other crypto buy. An on-ramp such as Banxa has moved money between fiat and crypto since 2014, with 100-plus payment methods across 100-plus countries. The flow: pick USDT, get a price locked for roughly 3 minutes, pass KYC the first time, pay, and the tokens land in your wallet, with card orders typically done within about 10 minutes of approval in the markets it serves. Cards cost roughly 3 to 5% all-in, bank transfers sit nearer 1% and suit larger amounts.

Before you tap buy, run through three checks. One: the network, matched to the wallet where the coins will land. Two: the address, first and last four characters at minimum. Three: your reason for holding a private company's dollar token instead of dollars. Sometimes that reason is excellent, just make sure you have one.