Stablecoins are crypto tokens pegged to a regular currency — almost always the US dollar. One token = roughly one dollar, all the time. They exist because traders and apps need a "stable" unit inside crypto that doesn't bounce around like Bitcoin does.

The two big ones, by a wide margin, are USDC (issued by Circle) and USDT (issued by Tether). Together they're worth over $200 billion. Both say they're backed 1:1 by real dollars. The interesting part is in how they back it, and what happens when something goes wrong.

What they do well — both of them

The boring stuff:

  • They hold roughly $1 in value. They move in tight ranges of $0.99-$1.01. Brief excursions outside that band happen during stress, but they always come back.
  • They move on multiple blockchains (Ethereum, Tron, Solana, etc.) so you can use whichever has cheaper fees.
  • You can hold them, send them, earn yield on them, pay with them. Functionally they're identical for daily use.

So why pick one over the other? Here's where they actually diverge.

How they're backed

Stablecoins explained: USDC vs USDT, in plain English (education)

USDC — Circle is a US company. They hold the dollar reserves at regulated US banks and short-term US Treasury bills. They publish monthly attestations from Deloitte showing exactly what backs the token. The reserves are transparent. The company is regulated by the New York Department of Financial Services and similar bodies elsewhere.

USDT — Tether is based in El Salvador. They hold reserves in a mix of US Treasuries, money market funds, secured loans, gold, Bitcoin, and a few other things. They publish quarterly attestations, but the reserves are less granular than USDC's. Tether has settled with the New York Attorney General over past reserve disclosures.

In normal markets, neither of those differences matters. In a crisis, they might.

Where each one wins

USDC tends to win for:

  • Users in countries with stricter regulation
  • Anyone with a low tolerance for "what if" reserve scenarios
  • Institutional flows (banks, fintechs, corporates) — they almost all prefer USDC
  • DeFi protocols increasingly default to USDC for collateral

USDT tends to win for:

  • Liquidity. USDT has more of it, especially outside the US, especially on the Tron network where fees are tiny.
  • Cross-border remittances and informal trading. Wherever the dollar is hard to get officially — Argentina, Nigeria, Turkey, parts of Southeast Asia — USDT is the actual money rail.
  • Asia-based exchanges. Bybit, OKX, MEXC all run on USDT-quoted pairs.

What happened in March 2023, and why it still matters

In March 2023, USDC briefly depegged to around $0.87 over a weekend. The cause: roughly 8% of USDC's reserves were held at Silicon Valley Bank, which had just collapsed. Circle disclosed the exposure on a Friday night. The market panicked all weekend. By Monday, the US government had guaranteed SVB deposits and USDC was back to $1.

That episode is the cleanest version of the USDC tradeoff: full transparency = you know exactly what could go wrong = you panic when something does. The depeg was real, brief, and ultimately fine. But people who sold at $0.87 lost real money.

USDT, by contrast, would have looked totally normal that weekend — but that's partly because we wouldn't have known about specific bank exposures the way we did with USDC.

Different risks. Not better or worse, exactly. Different.

Practical guidance

For most readers:

  • Hold both, lean USDC. USDC for savings-like storage and DeFi. USDT for trading on Asia-based exchanges if you do that.
  • Diversify the chain you hold them on. Ethereum is safest but slowest. Tron is cheap but more centralized. Solana is fast and cheap and worth using for small amounts.
  • Don't hold more in stablecoins than you'd hold in cash. They're not insured like a bank deposit. The peg is robust but not guaranteed.

The honest bottom line

Stablecoins are the single most useful innovation in crypto. They're the closest thing to "internet dollars" we've built. USDC and USDT are both fine. The differences only show up at the edges — and at the edges, USDC is usually safer and USDT is usually more liquid.

Crypto is volatile. Even "stable" coins can wobble. Don't hold more than you'd be willing to lose. None of this is financial advice.