Why do I get less than one USDC for one USDT even though both are dollar stablecoins

05 September 2026

You get less than one USDC for one USDT because the two stablecoins trade at a slight premium or discount to each other on the open market. Each is supposed to track one US dollar, but the mechanisms that enforce that peg are imperfect, and market supply and demand for each coin can diverge temporarily.

Both USDC and USDT are designed to be redeemable for one dollar from their respective issuers. In theory, this should keep them at parity. In practice, the secondary market where you swap between them reflects real-time imbalances.

The liquidity and redemption friction

Arbitrageurs normally keep stablecoins near parity. If USDT trades above $1.00 on an exchange, traders buy USDC, swap it for USDT, and sell the USDT for a profit. That activity pushes prices back together. But arbitrage is not instant, and it costs money.

When you swap USDT for USDC through an exchange or swap service, you are not redeeming with the issuer. You are trading on a market where order books reflect current bids and asks. If more people are selling USDT than buying it, the price of USDT dips relative to USDC. You then receive fewer USDC per USDT.

The same effect happens when USDC is under selling pressure: USDC loses value relative to USDT. The difference is usually tiny - fractions of a cent - but it is always there.

Market events that widen the gap

During periods of stress, the spread can grow. For example, during the March 2023 banking crisis, USDC depegged briefly because its issuer held reserves at a failing bank. USDC traded as low as $0.87 against USDT on some venues. Someone swapping USDT for USDC during that time would have received a lot more than one USDC, not less. The direction depends on which coin is under pressure.

Conversely, USDT has occasionally traded above $1.00 when demand spiked in specific markets, such as during rapid capital flight from exchanges or when off-ramps become clogged. In those moments, swapping USDT for USDC means getting fewer coins.

The swap route itself adds friction

When you convert USDT to USDC through an automated market maker, a centralized exchange, or a swap service, you pay a spread and often a fee. The spread is the difference between the buy and sell price of the token pair. Even in calm markets, that spread is not zero. The swap service might route through multiple hops - USDT to a different stablecoin to USDC - especially if you are moving across networks. Each hop shaves off a small amount.

If you are swapping on different blockchains, the problem compounds. USDT on Ethereum is an ERC-20 token. USDC on Solana is an SPL token. Moving from one chain to another requires a bridge or a yield/defi-stablecoin-depeg-cascade-risk/">swap through a liquidity pool that quotes a rate based on the relative supply of those tokens on each chain. If USDC is scarce on the destination chain, you get less.

What this means for your strategy

The variation is normal. It is not a flaw in any single stablecoin. It is the ordinary consequence of two separate assets that both aim at the same target but are not identical instruments. The difference is typically less than 0.1%, but during market dislocations it can widen to several percent.

You should check the rate before you confirm any swap. If the spread seems unusually large, wait. Imbalances often correct within minutes or hours as arbitrageurs step in.

This page sits under the hub titled "Swapping into and out of stablecoins". That hub covers broader strategies for moving between volatile assets and stable positions, including how to minimize friction when the spread is against you. It also addresses the specific differences between USDT on Ethereum and USDT on Tron, which are handled on a separate sibling page. For the full picture, read the hub after this.

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