Glossary term
Magic Formula Investing
Magic Formula investing is a rules-based stock strategy that ranks companies using earnings yield and return on capital.
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What Is Magic Formula Investing?
Magic Formula investing is a rules-based stock strategy popularized by Joel Greenblatt. It ranks companies using two ideas: buy good businesses and buy them at attractive prices. In the formula, quality is commonly represented by return on capital, while cheapness is represented by earnings yield.
The name sounds whimsical, but the method is disciplined value investing. It tries to avoid the two classic traps of buying cheap but poor businesses and buying good businesses at prices too high to produce attractive returns.
Key Takeaways
- Magic Formula investing ranks stocks by earnings yield and return on capital.
- The strategy seeks companies that are both inexpensive and high quality.
- It is rules-based, which reduces discretion but does not eliminate risk.
- The approach can underperform for long periods, especially when value-style strategies are out of favor.
- Investors should understand the screen, exclusions, taxes, turnover, and implementation costs.
How the Magic Formula Works
The basic process ranks a universe of companies by earnings yield and return on capital, then combines those rankings. Earnings yield is meant to identify companies that look cheap relative to operating earnings. Return on capital is meant to identify companies that generate strong profits relative to the capital used in the business.
The investor then buys a group of the highest-ranked stocks, holds them for a defined period, and repeats the process. The strategy is systematic: it depends on the screen and discipline rather than a narrative about each company.
The Two Core Inputs
Input | Plain-English role | What it tries to avoid |
|---|---|---|
Earnings yield | Looks for inexpensive companies | Overpaying for popular stocks |
Return on capital | Looks for efficient, profitable businesses | Buying cheap companies with weak economics |
Combined ranking | Looks for cheap and good together | Relying on valuation or quality alone |
How It Relates to Value Investing
Magic Formula investing is a subset of value investing, but it is more mechanical than traditional company-by-company analysis. A traditional value investor may study management, competitive advantage, accounting quality, industry structure, and intrinsic value. The Magic Formula compresses much of that judgment into two ranked measures.
That simplicity is both strength and weakness. A rules-based screen can keep emotion out of the process and make the strategy repeatable. But it can miss important qualitative information, accounting distortions, cyclical earnings risk, debt structure, and industry-specific realities.
Implementation Issues
Real-world results depend on more than the formula. The investable universe, market-cap cutoff, rebalancing schedule, tax treatment, transaction costs, liquidity, and whether financial or utility companies are included can all affect outcomes. A taxable investor who sells frequently may keep less of the gross return than a backtest suggests.
The strategy also requires patience. Cheap, high-return businesses can become cheaper before the market changes its view. A multi-year period of underperformance does not automatically mean the logic failed, but it can test whether the investor can actually follow the strategy.
Where It Can Mislead
No stock screen is magic. Earnings can be temporarily high, capital can be understated, and a business can look statistically cheap because the market correctly expects decline. A company with high return on capital may face new competition, regulation, or customer concentration. A low price can reflect real impairment.
In practical terms, Magic Formula investing is best read as a disciplined screen, not a complete investment process. It can identify candidates, but investors still need risk controls, diversification, and a clear implementation plan.
The Bottom Line
Magic Formula investing ranks companies by earnings yield and return on capital to seek stocks that are both cheap and high quality. It is a useful rules-based value strategy, but it still carries valuation, accounting, turnover, tax, and behavioral risks.