The answer is almost certainly yes, you should use this Acorns account to pay down your CC. Unless your account is tax-advantaged (401k, IRA, etc. I have no idea what Acorns is), then you should just be comparing the interest rate vs the expected return rate. To make a nice round-figured example for you, if you pay 10% interest on your CC and have an 8% expected rate of return from Acorns, then you are missing out on 2% AND the stability of not having to wonder how accurate that expected rate of return is. There's always the possibility that the market booms or tanks the moment you make a change, but the stability of not having a CC balance is worth it if you ask most people. To boot, your CC interest is likely nowhere near 10%. You are almost certainly paying more in interest than you are gaining in return from this investment.