If you are looking for a market with the most liquidity - USDC/BOND Uniswap Pool is definitely what you need.
Go to the BarnBridge App https://app.barnbridge.com/
On the top of the page beneath the Price info, click on the "Uniswap market" link and proceed to Uniswap.
Connect your wallet and enter the amount of USDC you want to swap and click Swap.
You will be prompted to pay a gas fee with Ethereum to perform the swap. Wait for the transaction to process.