Stocks are. A common pitch used to sell people on index funds involves bragging about annualized returns of stocks going back even longer than that, and compar

Stocks are. A common pitch used to sell people on index funds involves bragging about annualized returns of stocks going back even longer than that, and comparing them decade by decade against other asset classes such as real-estate and bonds. The implicit pitch is, "Look at this upward historical trend of stock valuations. If you invest in a fund that indexes them, you too will see these kinds of returns". Your point is good, though. Index funds never return quite as much as the underlying assets do since there are management fees. Over time, those fees compound.