Four different mechanical, value investing techniques were used. The first was the Magic Formula technique itself, consisting of rankings by composite earnings yield and adjusted return on capital. The second was Benjamin Graham's Net Current Asset Value (NCAV)technique from his famous book The Intelligent Investor
There are some nits to pick with the test itself. For one, the back-testing period is very short, just 10 years. Secondly, the test was applied to European stocks, not the U.S. market that the majority of MagicDiligence readers participate in. In reality, though, these are relatively minor issues. The past 10 years has been a fairly representative period, with two major downturns and a several year period of prosperity. And most studies have shown that the European markets behave very similarly to U.S. stocks.
So what are the relevant observations from the study data? There are 3:
1. Value-based Mechanical Investing Outperforms Blue-Chip Indexes. This is not really a surprise. All 4 value based strategies far outperformed the Stoxx index by significant margins across all market cap classes. This has been proven time and again by other studies (a good compendium is in the book What Works on Wall Street
2. Small-Caps Provide Better Returns in these Strategies. Another point proven by numerous studies. In MFIE's paper, the smaller the market cap class, the better the returns. The best performing strategy in the "top 20 over 50 million" study generated a 16.5% annual return, while the same strategy in the "top 20 over 5 billion" test returned just 2% per year. To really get the most out of these strategies, it is imperative to include small-cap stocks.
3. One Additional Screen Really Added Value to MFI. That was ranking the MFI stocks by Piotroski score. The Piotroski score method provided the best overall returns in 9 of the 13 back-tests, and was the "worst" of the 4 in just one test. It improved the annual return of the MFI strategy by 4.9% percentage points on average - an extremely significant number. What this seems to indicate is that MFI stocks with positive business momentum are the best performers over one-year holding periods. This correlates well with James O'Shaughnessy's findings in What Works on Wall Street.
Steve owns no position in any stocks discussed in this article.
Steve Alexander
[www.magicdiligence.com]
What Worked in the Stock Market for Long-Term Investors?
Extensive research has found that the companies with predictable revenues and earnings outperform the market average; they also suffer lower probability of loss. As a matter of fact, this kind of companies are exactly what Warren Buffett wants to buy and hold forever. Please read the research about what worked in the stock market:
Part I: What worked in the market from 1998-2008? Part I: Predictability Rank
Part II: Role of Valuations
Part III: Intrinsic Value, Discounted Cash Flow and Margin of Safety





