<prompt> Human: So I am going to have some extra money to do something with - like 1000 a month. I decided to open a mutual fund and called USAA to see what they had. Because I will need this money for a down payment on a house in 3-5 years, the broker suggested a low-risk fund with an expense ratio of about .6 which I thought was high, and which he said was low and an expected return of about 2. I would be better off paying down my existing 3.75 mortgage. I always thought investing would make more sense than paying down something that low, but this makes no sense to me. Thoughts?  <response>: I always thought investing would make more sense than paying down something that low, but this makes no sense to me.Investing in the market yes, investing in low risk fund, no. 