<prompt> Human: Hey all,The only debt I have now is my mortgage which feels great. I currently owe 174,000 on it. I have a 9 month emergency fund set aside. I maxed out all my 401K contributions 18k a year and my Roth IRA 5500k a year.After all my utility bills, mortgage, and spending cash, I have 4,300 extra a month to either contribute towards my mortgage or to invest in stocks, indexes, and or mutual funds.My mortgage interest rate is 3.63 on a 30 year fixed rate. So my question is do I use some or all or none of the 4300 to pay off the mortgage faster or do I invest that extra money into the above accounts where I could see an average return of around 6 to 7 ? My current thinking was to split it between extra mortgage payments and stocks. Any advice would be greatly appreciated. Thank you!  <response>: I was going to suggest doing both. Its still hard to find a 3.63 guaranteed after tax return, yet paying down the mortgage ties up your cash in a super illiquid asset. If you cant decide, splitting the difference is not a bad choice. 