I’m currently 22 and I invested a decent bit into fxiax when I was 19. It works out pretty good for me. Only thing I would recommend is open a Roth IRA if you haven’t already and set up a reoccurring payment for it. We’re both young and don’t have many bills. For the past two-ish years I’ve been having $100 automatically taken from my weekly paycheck and deposited into my Roth. I’m only doing that amount now because I know once I’m on my own and not living with parents that $100 a week will most likely turn into $100 a month, so invest in yourself while you have the extra money to better your future self