The Little Book of Stock Market Profits

What this book actually teaches

The Little Book of Stock Market Profits: The Best Strategies That Work (2011) by Mitch Zacks is a practitioner's review of systematic stock selection strategies, written by the president of Zacks Investment Research, whose firm has spent decades analyzing what actually predicts stock returns. The book's thesis is that certain quantifiable factors — particularly earnings estimate revisions and earnings surprises — have demonstrated persistent predictive power for equity returns, and that investors who build strategies around these factors can improve on market returns on a risk-adjusted basis.

Zacks dedicates the core of the book to what his firm calls the Zacks Rank, a proprietary model built primarily around earnings estimate revisions. The logic is straightforward: when sell-side analysts revise their earnings estimates upward for a company, those revisions tend to underreact to the new information — meaning the stock continues to drift in the direction of the revision for a period after the announcement. Buying stocks with recent upward earnings estimate revisions and shorting or avoiding stocks with downward revisions has historically captured this drift. Zacks presents historical backtest data showing the model's track record and explains the underlying behavioral mechanism.

Beyond the core earnings revision factor, the book reviews several other systematic strategies that have shown evidence of working over time: momentum (stocks that have outperformed recently tend to continue outperforming in the near term), value factors (price-to-earnings, price-to-book, price-to-sales), and growth factors (earnings growth rate and consistency). Zacks treats these as potentially combinable inputs into a screening-based selection process rather than as standalone strategies.

The book is candid about several limitations. Factor strategies go through extended periods of underperformance relative to the market — value investing underperformed significantly during the late-1990s growth bubble, for instance — and investors who cannot tolerate those drawdowns behaviorally will abandon the strategy at the worst time. The strategies also require consistent execution over time; sporadic application eliminates the statistical edge that comes from systematic application across many positions.

The weaknesses are primarily about depth and currency. Zacks describes the strategies at a conceptual level but does not provide enough implementation detail — how many stocks to hold, how frequently to rebalance, how to handle position sizing and transaction costs — for readers who want to execute systematically without additional research. The book was also published before the widespread availability of factor ETFs and smart beta products that now allow investors to capture many of these documented factors at low cost without individual stock selection.

For investors who want to understand the evidence base for systematic equity factor strategies — why earnings revisions, momentum, and value factors have historically worked and what the behavioral mechanisms behind them are — The Little Book of Stock Market Profits offers a clear, evidence-grounded introduction. Implementation requires supplementing with more specific guidance on portfolio construction and current factor products.

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About Mitch Zacks

Read more from Mitch Zacks and explore the full bibliography on ClearValue Books.