Overview
Tether (USDT) is the world’s largest stablecoin: a token designed to always be worth one US dollar. It launched in 2014 and is issued by Tether, a company led by CEO Paolo Ardoino and headquartered in El Salvador since 2025.
USDT is the most-used token in crypto. Traders use it to move between coins, and millions of people in countries with unstable currencies use it to save and send dollars. In October 2026, about $183 billion of USDT was in circulation, roughly 60% of all stablecoins, according to DeFiLlama.
How it works
- Tether issues new USDT when customers (mostly large firms) send it dollars.
- It invests those dollars in reserves, mostly short-term US Treasury bills.
- When customers redeem USDT, Tether returns dollars and destroys the tokens.
USDT runs on many blockchains, with most of it on Tron and Ethereum. Holding USDT earns you no interest; Tether keeps the interest from its reserves, which has made it one of the most profitable companies in the world per employee, with profits in the billions every year.
Reserves and transparency
Tether publishes quarterly attestations from the accounting firm BDO showing its reserves. These are checks at a point in time, not a full audit. Most reserves are US Treasuries, but Tether also holds bitcoin, gold, secured loans and other investments, plus an extra buffer of several billion dollars above what it owes.
Tether’s history includes controversy: in 2021, US regulators fined it a total of about $60 million (the CFTC and the New York Attorney General) for misleading claims about how its reserves were backed in earlier years.
USAT and the GENIUS Act
In July 2025, the US passed the GENIUS Act, the first federal law for stablecoins, requiring safe reserves and regular audits. Its main rules take effect in January 2027, and from July 2028 US platforms may only offer approved stablecoins.
Tether’s answer was USAT, a separate US-regulated stablecoin issued through Anchorage Digital Bank and run by former White House crypto adviser Bo Hines. USAT is still small, about $180 million in October 2026. Critics argue USAT lets USDT continue outside US rules, since part of USDT’s reserves would not qualify under the law.
The USDT token
| USDT at a glance | |
|---|---|
| In circulation (Oct 2026) | about $183 billion |
| Target value | $1.00 |
| Lowest point in a major crisis | about $0.95 (May 2022, briefly) |
| Market cap | about $183 billion (#3) |
| Main blockchains | Tron, Ethereum and many others |
Risks
- Depeg risk. If people lost trust in Tether’s reserves, USDT could fall below $1. It has always recovered so far, including after briefly dropping to about $0.95 during the 2022 Terra collapse.
- Freezing. Tether can and does freeze USDT at addresses linked to hacks, scams or sanctions. This helps fight crime but means your USDT is never fully under your control.
- Regulation. The GENIUS Act and Europe’s MiCA rules limit where USDT can be offered; some EU exchanges have delisted it for EU users.
- Concentration. A failure at Tether would shake the entire crypto market.
Tether vs. the competition
| USDT | USDC | DAI / USDS | |
|---|---|---|---|
| Issuer | Tether | Circle (US-listed company) | Sky (DeFi protocol) |
| Market share | ~60% | ~24% | Smaller |
| Reserves | Mostly T-bills, plus BTC, gold, loans | Cash and T-bills only | Crypto and real-world assets |
| Independent audit | Attestations | Attestations + audited parent | On-chain transparency |
| US / EU regulated | Via USAT only | Yes (MiCA, US) | No |
Our verdict
Tether is crypto’s most important stablecoin: the most-used, most-liquid way to hold dollars on a blockchain, with a long record of keeping its peg and very large profits behind it.
But it asks for more trust than its main rival: no full audit, some riskier reserves and an uncertain fit with new US and EU rules. USDT is a useful tool, not an investment: it doesn’t grow in value. Many users split their stablecoins between USDT and USDC to spread the risk.
This review is for information only and is not financial advice.