The strong form of the EMH is obviously an overstatement. It does not admit the possibility of gaining from inside information. Nathan Rothschild mad… - Burton Malkiel

This chapter’s review of the Internet and housing bubbles seems inconsistent with the view that our stock and real estate markets are rational and efficient. The lesson, however, is not that markets occasionally can be irrational and that we should therefore abandon the firm-foundation theory of the pricing of financial assets. Rather, the clear conclusion is that, in every case, the market did correct itself. The market eventually corrects any irrationality—albeit in its own slow, inexorable fashion. Anomalies can crop up, markets can get irrationally optimistic, and often they attract unwary investors. But, eventually, true value is recognized by the market, and this is the main lesson investors must heed.
I am also persuaded by the wisdom of Benjamin Graham, author of Security Analysis, who wrote that in the final analysis the stock market is not a voting mechanism but a weighing mechanism. Valuation metrics have not changed. Eventually, every stock can only be worth the present value of its cash flow. In the final analysis, true value will win out.

With these broad time periods set, let us now look at how the determinants of returns developed during those eras and look especially at what might have been responsible for changes in valuation relationships and in interest rates. Recall that stock returns are determined by (1) the initial dividend yield at which the stocks were purchased, (2) the growth rate of earnings, and (3) changes in valuation in terms of price-earnings (or price-dividend) ratios. And bond returns are determined by (1) the initial yield to maturity at which the bonds were purchased and (2) changes in interest rates (yields) and therefore in bond prices for bond investors who do not hold to maturity.

Investors should certainly be aware of new methods of portfolio construction. And high net worth investors might consider adding a multifactor smart beta offering or a risk-parity portfolio to the overall mix of their investments. Factor investing can potentially increase returns at the cost of assuming a somewhat different set of risk exposures than those of a standard broad-based index fund. And investors who are able to accept the added risks inherent in leverage might profitably add a risk-parity portfolio to their set of investments. Such offerings should only be considered, however, if they are low cost and if their potentially adverse tax effects can be offset in other parts of the overall portfolio. And I continue to believe that a broad-based total stock market index fund should be the core of everyone’s portfolio. Certainly, for investors who are starting to build an equity portfolio in planning for retirement, standard capitalization-weighted index funds are the appropriate first investments they should make.