No - Aven does not take possession or custody of your bitcoin.
You will need to deposit bitcoin with Aven’s custodian BitGo as collateral for the Aven Bitcoin Visa Card. You can add or withdraw bitcoin or funds over time. Any deposited bitcoin must be kept in your Aven account for at least seven consecutive days before it is eligible for withdrawal.
You can view the excess bitcoin available to withdraw from your Aven Bitcoin Visa Card in the Aven app.