Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Should I use put extra money toward paying off my student loans or investing in an index fund?
From a purely financial standpoint (psychology aside) the choice between paying off debt and investing on risky investments boils down to a comparison of risk and reward.  Yes, on average the stock market has risen an average of 10% (give or take) per year, but the yearly returns on the S&P 500 have ranged from a high of 37.6% in 1995 to a low of -37% in 2008.  So there's a good chance that your investment in index funds will get a better return than the guaranteed return of paying off the loan, but it's not certain, and you might end up much worse.  You could even calculate a rough probability of coming out better with some reasonable assumptions (e.g. if you assume that returns are normally distributed, which historically they're not), but your chances are probably around 30% that you'll end up worse off in one year (your odds are better the longer your investment horizon is).  If you can tolerate (meaning you have both the desire and the ability to take) that risk, then you might come out ahead.   The non-financial factors, however - the psychology of debt, the drain on discretionary cash flow, etc. cannot be dismissed as "irrational".  Paying off debt feels good.  Yes, finance purists disagree with Dave Ramsey and his approaches, but you cannot deny the problems that debt causes millions of households (both consumer debt and student loan debt as well).  If that makes them mindless "minions" because they follow a plan that worked for them then so be it. (disclosure - I am a listener and a fan but don't agree 100% with him)