<prompt> Human: I tried searching but didnt see anything like this. I just transferred to a new school, after scholarships and money I put up I had to take out loans and I received a direct loan of 12.5k. 5k was subsidized and 7k wasnt. I used 9K and told the school to manage my funds and return the excess, I asked if they needed written notice and they said no, turns out I DID have to give them a written notice. Long story short, I received a check for about 3K. Im still within the 120 day disbursement period, so I can just deposit the check and make the payment. My 401k gave me really good returns last year, way more then 3.85 interest rate of un-subsidized loan. I am considering dumping that 3k into a mutual fund with Vanguard or Fidelity my current 401k provider and lock it up for 2 years date of graduation, Im hopeful that Id accrue more than the 3.85 in two years I got 30 return last year so when I graduate I could repay back the orignal 3K and whatever returns I gained. I know this is a risk but if I get even a modest 8 return for the two years, its still more than the 3.85 original loan interest.Thoughts?  <response>: for what its worth, i am 26 and am just now really realizing how expensive my student loan debt is and how badly i need to get rid of it. if i could go back, id send every extra penny back to the lender to reduce my debt up-front. Every. Penny. yes, its nice to have that cushion in your checking account, its nice to hope for that 8 return. but its not guaranteed. returning the excess to the lender is a guaranteed return. Former higher education financial aid counselor here. 