Native USDC bridging with CCTP V2
How Earn moves USDC across chains using Circle's CCTP v2.
When the best vault lives on another chain, Earn moves your USDC through Circle's CCTP v2. Circle burns the USDC on the source chain and mints native USDC on the destination chain. No wrapped token, no bridge custodian.
The four steps
Burn
On a rebalance, Earn first takes its fee in shares of the source vault (see Fees and gas), then redeems the remaining shares to USDC and burns that USDC on the source chain. On a close or a Reduce, your own transaction does the redeem and the burn.
Attestation
Earn waits for Circle's Iris API to attest the burn. On most chains this is the slowest step.
Mint
Earn submits the attestation on the destination chain and CCTP mints the USDC. Quicknode pays the destination-chain gas, except on a Reduce, which pays a relay fee for it. See Who pays gas.
Deposit
In the same transaction, the USDC deposits into the new vault and the position starts earning.
Closes and a Reduce skip step 4: the minted USDC goes straight to your wallet.
On a deposit or rebalance, the target vault can refuse the funds when they land: it is at capacity, hidden, paused, or already held by this strategy. Earn then deposits into the highest-ranked approved vault (see Rebalancing) that passes a live deposit check. The amount never changes. An Increase is the exception: it waits for its own vault rather than going elsewhere.
While a bridge is in flight, the strategy page shows a Bridging card with one row per transfer. Its status runs Sending, Confirming with Circle, then Depositing on the destination chain, or Sending to your wallet on a withdrawal. The row drops off when the funds land. The progress bar fills to 90% over Circle's estimated attestation time and waits there if the attestation runs late. The last 10% covers the mint and the deposit.
Supported chains and timing
Earn uses CCTP's standard transfer, which waits for full chain finality. Circle charges no fee for it.
| Chain | Worst-case attestation |
|---|---|
| Ethereum | ~19 minutes |
| Optimism | ~19 minutes |
| Arbitrum | ~19 minutes |
| Base | ~19 minutes |
| Polygon | ~8 minutes |
| Unichain | ~19 minutes |
| Monad | ~5 seconds |
Earn checks for new attestations about once a minute, so a Monad bridge waits for the next check, not for the attestation.
If a bridge stalls
The burn message does not expire, and no escrow holds the USDC in flight, not Earn and not a third party. Earn retries the mint every minute, and a reverted mint consumes nothing, so a stalled bridge lands in the end. On a Reduce, Earn defers a mint for up to an hour, rather than mint at a loss, when gas pushes its cost above twice the quoted fee or the fee plus 1 USDC, whichever is higher.
On a close, anyone can submit the mint, and the USDC lands in your wallet. On a deposit or rebalance, only the Earn contract can complete the mint into the vault. If an inbound deposit bridge is still pending 30 minutes after the burn, the Bridging card shows Claim to wallet. The contract accepts the claim only from the wallet that started the bridge, and the minted USDC goes to that wallet instead of the vault. Deposit it again if you want it back in the strategy.