The Efficient Market Hypothesis

So what is the "Efficient Market Hypothesis" and how does it apply to investing? This theory states that it is impossible to "beat the market" because the "efficiency" of the stock market causes existing share prices to always incorporate and reflect all relevant information. If this theory is true, it is nearly impossible to outperform the overall market, and higher returns can only be obtained by buying riskier investments.

A common perception about investment managers and "Wall Street" is that there are some super-smart people out there that know how to make money from investing in ways that no one else does. History has proven that the vast majority of "active" (those who use expert stock selection or market timing) managers do not outperform the markets as a whole. In most cases, the higher than market returns are obtained by taking on additional risk. Many on "Wall Street" also become wealthy by charging unnecessarily high fees for their advice.

If this hypothesis is correct, then what is the best approach to investing? For most people, index funds, exchange-traded funds, or low-cost mutual funds are the answer. Diversification, portfolio rebalancing and reducing costs are the three factors that can best increase portfolio values over time without taking on more risk than the individual would normally be comfortable taking. Like most fields, there are some true principles of investing, and I believe that the "Efficient Market Hypothesis" is one of these principles. I recommend that you look at this article and video for more discussion and advice on this topic.