<prompt> Human: Maybe this is a stupid question, but it seems most people on here subscribe to investing into SPY or something similar because of the low fees and the fact that 90 of funds do not beat the market. But, here we have QQQ NASDAQ Index Fund which has a similarly low expense ratio, yet its 10 year annual return is 14.10 vs 9.05 for SPY. Am I missing something why we should be investing in the SP instead of the NASDAQ. I would think that most of us agree that, in the long run, the market will go up more than it will go down. So, why not invest into NASDAQ with a beta of 1.19 vs 1.0 of the SP? Since the market will go up more than it will go down, based on the beta, the NASDAQ will produce better returns during bull markets and worse during bear markets. But bull markets last longer than bear, on average. Please tell me where I am going wrong with my thought process.sources:  <response>: The NASDAQ is heavily weighted toward tech companies. If Tech companies are booming as they have for the last decade it will out perform; however in the event of another tech bubble pop it will fall far more.SPY is also far more diverse company-wise as well. Look at the holdings tab on your link. Apple, Microsoft, Amazon alone account for 13 of QQQ, vs 110th of SPY. 