The Geometry of Stock Market Profits

What this book actually teaches

The Geometry of Stock Market Profits (1991) by Michael Jenkins is a technical analysis manual organized around the application of geometric price-and-time relationships — angles, ratios, squares, and cycles — to stock and commodity charts. Jenkins draws heavily on the methodology of W.D. Gann, the early twentieth-century trader and theorist who argued that price movements in financial markets follow mathematical and geometric laws that can be identified and traded. The book's central premise is that price and time are related through geometric constants, and that by drawing specific angle lines and identifying key price-time coordinates on charts, traders can project future price levels and turning points with meaningful accuracy.

The book covers a range of techniques associated with Gann analysis: the 1x1 angle (45-degree line representing one unit of price per unit of time), other angles derived by dividing the price and time axes into fractional relationships (1x2, 2x1, 1x4, etc.), the use of price squares to project resistance and support levels, and the application of natural number cycles to identify time windows where reversals are more likely. Jenkins works through chart examples to illustrate how these geometric constructs would have identified significant market turning points in historical data.

For readers willing to engage seriously with Gann-derived methodology, the book provides one of the more technically detailed presentations of geometric price analysis available in the literature. Jenkins writes with practitioner conviction and works through his examples with enough specificity that readers can attempt to apply the techniques to their own charts. The chapter on squaring price and time — the idea that significant reversals occur when a market's price range and time duration reach proportional balance — is representative of the approach: internally consistent within its own framework and empirically testable in principle, though the selection of examples makes objective evaluation difficult.

The weaknesses are substantial and should be understood before investing time in this material. Gann-derived geometric methods have not been validated through rigorous out-of-sample testing in peer-reviewed research. The technique of drawing lines on charts that retroactively touch significant highs and lows is vulnerable to hindsight bias — it is nearly always possible to find a geometric relationship that explains past price action, but the track record of forward-looking geometric price projections is not systematically documented. The academic consensus on technical analysis as a whole is that the more complex and theory-heavy approaches, including Gann geometry, have the weakest empirical support relative to simpler momentum and trend-following indicators.

Readers interested in Gann methodology should treat this book as an advanced practitioner text within a school of technical analysis that is controversial among quantitative researchers. It is not an appropriate starting point for most investors, and claims about predictive accuracy should be evaluated skeptically without independent out-of-sample verification.

For technically oriented traders who are already familiar with Gann analysis and want a detailed treatment of geometric price-time methods — and who approach the material critically rather than as confirmed predictive science — Jenkins's book is among the more thorough resources in this corner of technical analysis literature.

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About Michael Jenkins

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