Tether

Launched in 2014, Tether (USDT) was the first dollar-pegged stablecoin to reach mass adoption and remains the largest by circulating supply today, with well over $150 billion in tokens outstanding. Rather than living on one chain, USDT is issued across many networks at once, including Ethereum, Tron, and Solana, so traders can move dollar-equivalent value between exchanges and wallets without waiting on a bank wire.

The issuer, Tether Limited, maintains a reserve portfolio to back each token, made up mostly of short-term US Treasury bills, with smaller shares in overnight repurchase agreements, money market funds, and other assets such as Bitcoin and precious metals. Independent accounting firms publish quarterly attestations confirming reserves exceed liabilities, but Tether has not yet completed a full audit to Generally Accepted Accounting Principles standards, a gap critics have raised for years even as the company reports large quarterly profits from Treasury interest.

Because it sits at the center of crypto trading, holding a huge share of pairs on centralized exchanges and much of the liquidity on decentralized platforms, USDT's dollar peg is closely watched: a sustained deviation from $1 can ripple through the entire market. New rules such as Europe's MiCA framework have already pushed some regulated exchanges to delist USDT for EU users, while US legislation is reshaping how dollar-backed stablecoins are supervised.