If you're a busy investor with more than just stock-picking on your plate, you might want to consider a mechanical investing strategy. And if you're interested in stocks, one of the most intriguing of these strategies is Joel Greenblatt's Magic Formula.

Greenblatt details this approach in his enriching, funny The Little Book That Beats the Market. His strategy revolves around two factors:

  • How cheap is the stock?
  • How profitable is the company?

This simplified approach really boils down value investing to its essence. When you find a company whose price fails to reflect its high profits, you might have a winner.

A cheap business and a profitable company
To find cheap companies, the Magic Formula looks for a high earnings yield -- basically, a company's EBIT divided by its enterprise value. EBIT is earnings before interest and taxes, otherwise known as operating earnings. Enterprise value includes the company's market capitalization, then adds its net debt. In general, the higher the earnings yield, the better. The Magic Formula looks for a yield higher than 10%.

To find profitable companies, Greenblatt's Magic Formula seeks businesses that generate returns on assets (ROA) greater than 25%. In other words, for every $100 in assets it holds, the company would produce at least $25 in net profit. In general, the higher the ROA, the better the business. Greenblatt looks for companies with an ROA higher than 25%.

So how do these education companies fare?


Enterprise Value


Earnings Yield


Bridgepoint Education (NYSE: BPI) $1,010 $252 25.0% 34.3%
Apollo Group (Nasdaq: APOL) $5,500 $1,373 25.0% 28.1%
Corinthian Colleges (Nasdaq: COCO) $578 $174 30.2% 9.8%
ITT Educational Services (NYSE: ESI) $2,128 $612 28.7% 55.4%

Source: Capital IQ, a division of Standard & Poor's. Trailing-12-month figures.

Bridgepoint Education, Apollo Group, and ITT Educational Services all meet both of the Magic Formula criteria. ITT looks especially good, with an earnings yield exceeding 28% and an ROA above 55%. Corinthian Colleges far exceeds the formula's desired 10% earnings yield, but its ROA is below 10%, which is more than 15 percentage points away from the formula's desired 25%. While these numbers look very good, investors would be wise to examine pending regulation that could drastically affect these for-profit educators.

Foolish bottom line
The key advantage of the Magic Formula is speedy decision-making. You can run a screen and mechanically buy the stocks, then spend your free time doing the activities you love. However, such an approach means that you need to pick a lot of stocks (say, 25 or 30), since you haven't performed any strategic analysis of your investments. According to the formula, you should hold the stocks for one year in order to receive favorable tax treatment, sell all of them, and then run the screen again to find your new picks.

While this approach sounds easy, Greenblatt cautions that it can be tough to stick with during hard times. In some years, this mechanical strategy simply won't work. However, Greenblatt's extensive backtesting suggests that over the long haul, his Magic Formula can significantly outperform the market.

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Jim Royal, Ph.D., does not own shares of any company mentioned. The Motley Fool owns shares of Bridgepoint Education. Motley Fool newsletter services have recommended creating a call spread position in Bridgepoint Education. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insightsmakes us better investors. The Motley Fool has a disclosure policy.