You can transfer funds from a secondary portfolio to your trading balance on Coinbase Prime.
From the portfolio tab, search for the asset.
Click the asset to open the asset page.
Under Trading Balance, click Deposit
Click Transfer from Trading Balance.
Select the portfolio and wallet you’ll be transferring from.
Enter the amount.
Click Preview Transfer.
Review the details, then click Initiate Transfer.
Verify your identity using a physical security key.
This action may require additional consensus approvals before it’s processed.