Skip to content
guides savings security

USDC vs USDT: Understanding the Two Largest Digital Dollars

Learn how USDC and USDT work, what backs each one, and how they compare on reserves, transparency, and regulation. A factual guide to the two digital dollars most people hold.

USDC market cap

$62 billion

USDT market cap

$145 billion

Combined market share

80%+

GENIUS Act compliance deadline

Late 2026 / Early 2027

USDC and USDT together represent over 80% of the total digital dollar market, roughly $207 billion in combined value as of early 2026. Both are designed to hold a steady 1:1 value with the US dollar. Both can be held in a wallet on your phone. And under the GENIUS Act, both issuers will need to meet the same federal requirements.

This guide covers how each one works: what backs them, how they’re verified, and how they’ve performed. If you’re new to the concept, start with what digital dollars are.

Who issues each one?

USDC is issued by Circle, a US-based financial technology company headquartered in Boston. Circle holds state money transmitter licenses and has operated under US regulatory oversight since 2013. Its market cap sits at approximately $62 billion.

USDT is issued by Tether Limited, incorporated in the British Virgin Islands. Tether launched USDT in 2014, making it the oldest and most widely used digital dollar globally. Market cap: approximately $145 billion. That’s the largest of any digital dollar by a wide margin.

They serve the same basic function: letting you hold dollar-denominated value digitally. The differences show up in how they operate behind the scenes.

How reserves work

Every digital dollar is meant to be backed 1:1 by real assets. Here’s how each issuer handles that.

USDC reserves sit in the Circle Reserve Fund, an SEC-registered government money market fund managed by BlackRock. The fund holds short-term US Treasury bills and overnight repurchase agreements. Circle publishes the full composition in monthly attestation reports verified by Deloitte.

USDT reserves are spread across a mix of assets. According to Tether’s attestation reports, the majority is now in US Treasury bills, with the remainder in cash equivalents, precious metals, and other holdings. Tether publishes quarterly attestation reports prepared by BDO Italia.

USDC (Circle)USDT (Tether)
Primary reservesUS Treasury bills, cashUS Treasury bills, cash equivalents
Other reservesNone disclosedPrecious metals, other holdings
Reserve structureSEC-registered fund (BlackRock)Company-managed
Attestation frequencyMonthlyQuarterly
Attestation firmDeloitteBDO Italia
Issuer headquartersUnited StatesBritish Virgin Islands

Both approaches end up with reserves primarily in US government debt. Where they differ is structure, how often verification happens, and the asset mix.

Transparency and verification

Circle publishes monthly attestation reports and in 2024 began publishing near-real-time reserve data. Deloitte, one of the Big Four firms, verifies these reports.

Tether publishes quarterly attestation reports prepared by BDO Italia. In 2021, Tether settled with the New York Attorney General for $18.5 million over past reserve misrepresentations, and paid a $41 million CFTC fine for the same period (2016 to 2019). Since then, Tether has significantly improved its reserve disclosures and shifted reserves toward US Treasuries.

One thing worth knowing: neither USDC nor USDT has undergone a full financial audit in the traditional sense. Both publish attestation reports, a more limited form of verification where a firm confirms specific facts at a point in time.

The GENIUS Act: a common baseline

The GENIUS Act, signed into law on July 18, 2025, established the first US federal regulatory framework for digital dollar issuers. It sets requirements that apply equally to both:

  • 1:1 reserve backing in approved assets (cash, Treasury bills, government money market funds)
  • Asset segregation: reserves can’t be mixed with operating funds or used for lending
  • Redemption rights: holders must be able to redeem at par on demand
  • Monthly public reporting of reserve composition
  • Penalties of up to $500,000 per violation for misleading claims

Full enforcement extends into late 2026 or early 2027. Once it’s fully in effect, both issuers will need to meet the same standards. For more on the law, see what the GENIUS Act is.

Peg history

Both USDC and USDT have temporarily traded below $1.00. Neither has failed to recover.

USDC, March 2023. Circle disclosed that approximately $3.3 billion of reserves were held at Silicon Valley Bank, which had just been shut down by regulators. USDC dropped to roughly $0.87 over that weekend. When the US government announced all SVB depositors would be made whole, USDC returned to $1.00 within 48 hours. Circle subsequently moved all reserves into the BlackRock-managed fund.

USDT, October 2018 and May 2022. USDT dropped to approximately $0.92 in October 2018 amid concerns about Tether’s financial relationships. In May 2022, following the TerraUSD collapse, USDT briefly traded at $0.95 on some exchanges. Both times it recovered.

EventDigital dollarLowDurationOutcome
SVB collapse (Mar 2023)USDC~$0.87~48 hoursFull recovery
Trust concerns (Oct 2018)USDT~$0.92~1 weekFull recovery
TerraUSD fallout (May 2022)USDT~$0.95~48 hoursFull recovery

Temporary depegs are a real feature of digital dollars. In all documented cases for both USDC and USDT, holders who waited recovered full value. For a broader look at risk, see can you lose money holding digital dollars.

Side-by-side summary

FactorUSDC (Circle)USDT (Tether)
Market cap~$62 billion~$145 billion
Launch year20182014
Issuer locationUnited StatesBritish Virgin Islands
Primary reservesUS Treasuries, cashUS Treasuries, cash equivalents
Attestation frequencyMonthlyQuarterly
Attestation firmDeloitteBDO Italia
Real-time reserve dataYesNo
Global liquidityHighHighest
GENIUS Act statusBoth must comply by late 2026 / early 2027Both must comply by late 2026 / early 2027

How people use them

Different people pick USDC and USDT for different reasons:

  • People holding savings long-term often lean toward USDC for its more frequent reserve verification.
  • People who need to move dollars quickly or convert to local currencies tend to use USDT because it has deeper liquidity on more platforms worldwide.
  • Many people hold both, keeping each for different purposes. This also spreads exposure across two separate issuers.

There’s no single right answer. What matters most is understanding what you hold and keeping it in a wallet where you control your own keys. Arca supports both USDC and USDT, letting you hold either or both in a single wallet.

For more on how wallet choice affects your security, see the difference between wallet types. To understand what happens if an issuer runs into trouble, see what happens if a digital dollar issuer goes bankrupt.

Your dollar wallet. No bank needed.

Hold dollars, send them instantly, and manage your money on your terms.

Get started with Arca
Get started with Arca