<prompt> Human: When I look at some technology mutual funds offered by Fidelity, they have a track record that beats the SP 500 over 30 years by 5, ie 16 vs 11 after taxes. Is there a reason everyone says invest in a broad market index fund when frankly these funds look strictly better over the long run?  <response>: Because past performance doesnt predict future results. In the 90s some of us lost money on this catastrophe. x200B;Also be careful of survivorship bias. You are comparing the SP 500 to tech mutual funds that survived and thrived. Youre not comparing it to the ones that failed and were dissolved by Fidelity etc. 