I mentioned the math of saving even one Starbucks trip per week to my wife, and she was surprised about the possible amount saved over 20 or 30 years. I'm glad she was excited about getting those savings. But her next request surprised me: Could we do exactly the aforementioned exercise? Meaning we make less starbucks trips, but every time we consciously eliminate one, we put the money we would've spent there into an account, invest it, and watch how much it actually becomes over the years. I mentioned that funds have certain minimums, so it wouldn't be possible to invest something like $20 on its own. We could roll it in with our other investments, keep track of the return over the years, and manually do the math to see what the initial $20 became. But she was more interested in pooling just the starbucks savings, and having a single, simple spot to check to see what's become of it. Is such a thing possible? Can one somehow invest something like $20 in an account on its own?