Cost matters hypothesis
The overarching reality is simple: Gross returns in the financial markets minus the costs of financial intermediation equal the net returns actually delivered to investors. Although truly staggering amounts of investment literature have been devoted to the widely understood EMH (the efficient market hypothesis), precious little has been devoted to what I call the CMH (the cost matters hypothesis). To explain the dire odds that investors face in their quest to beat the market, however, we don't need the EMH; we need only the CMH. No matter how efficient or inefficient markets may be, the returns earned by investors as a group must fall short of the market returns by precisely the amount of the aggregate costs they incur. It is the central fact of investing.
— John C. Bogle, The Relentless Rules of Humble Arithmetic, Financial Analysts Journal; November/December 2005
This is a core element of the Bogleheads® investment philosophy.
- Bogle, John C.,The Relentless Rules of Humble Arithmetic, Financial Analysts Journal; November/December 2005. Viewed January 20, 2015.