Back when a stock trade used to cost $20 or more in commissions alone, and needed to be entered manually, buying a no-load index fund was not only an easier way to accumulate a diversified stock portfolio, but also significantly cheaper than buying a portfolio of stocks directly. Over time, assets of these no-load index funds became so massive that they needed to diversify into a market cap weighted portfolio of nearly every stock in the market, regardless of valuation, simply to scale. Like a package of processed food, these funds have "processed" their ingredients