Moving Average: Holy Grail or Fairy Tale - Part 3
July 28, 2009
by Theodore Wang
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This article is the latest in a series by Theodore Wong. The others were What the “Missing Out” Argument Misses, Moving Average: Holy Grail or Fairy Tale - Part 1, and Moving Average: Holy Grail or Fairy Tale - Part 2.
“If there was ever a good time to consider a new investment approach,” an advertisement for a mutual fund company proclaimed in a recent issue of a financial planning magazine, “it’s when the old ones have proven so fallible.” For a second, I thought that they had finally given up on the tired buy-and-hold (B/H) approach. It turned out they were just promoting a new kind of index fund.
Buy-and-hold remains deeply entrenched in the financial planning community, despite many of the flaws my previous articles have illustrated. Although many financial advisors suffer dearly from their B/H practices, they are reluctant to change their approach. Who dares to challenge investment sages like Bogle, Siegel, and Malkiel who emphatically support this long-standing investment principle? Academic research studies overwhelmingly endorse B/H. How can they all be wrong?
Perhaps the investment scholars and researchers are right to advocate B/H, but for the wrong reason, as I will explain later. But first, let me digress to respond to some of the feedback my previous articles received.
Let’s be clear
I am gratified to learn that many readers are able to replicate my results. My research is only credible if it passes peer reviews. A couple of readers, however, had difficulty reproducing my exact numbers. I use Professor Robert Shiller’s S&P500 Index primarily because his data is accessible to the public, so that my calculations can be checked. But Professor Shiller creates his monthly index by averaging daily closing prices. If you use actual daily or monthly closing prices, you will get different results.
Several analysts also inquired about the actual implementation of the Moving Average Crossover (MAC) system. For the record, it is not my intention to promote the MAC system as a trading tool. There are many trading systems used by active managers with proven track records. I use MAC as a demonstration to challenge the popular notion that no one can beat the markets in the long run. In science, it only takes one counterexample to invalidate a principle, no matter how well-established it might be.
Establishing a way to implement active investment management systems into a business practice exceeds the scope of my articles. For those planners new to the field of rule-based trading systems, my advice is to work with a reputable active investment firm or to use experienced consultants. It’s not a do-it-yourself project.