Your Round-ups sources have a different function from your funding source. While your Round-ups sources are also external bank accounts that you connect to Peak though Plaid, they're only function is to track your daily spending in order to attain Round-ups. As opposed to a funding source, Round-ups sources are completely optional within Peak, and we will never move money in or out of your Round-ups source. A great choice for a Round-ups source would be your credit card or any other account you commonly use for every-day purchases. Also, if you so choose, it is also possible to pick the same bank account, a checking account, to use as both a funding source and a Round-ups source.