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"...forty years after I started battle on the subject, most economists now acknowledge that prices do not follow the bell curve, and do not move independently. But for many, after acknowledging those points, their next comment is: So what? Independence and normality are, they argue, just assumptions that help simplify the math of modern financial theory. What matters are the results. Do the standard models correctly predict how the market behaves over all? Can an investor use Modern Portfolio Theory to build a safe, profitable investment strategy? Will the Capital Asset Pricing Model help a financial analyst, or a corporate financial officer, make the right decision? If so, then stop arguing about it. This is the so called positivist argument, first advanced by University of Chicago economist Milton Friedman." Isn't it this positivism that the majority of practitioners of finance exhibit? I myself, though not a practitioner, held such thoughts. My reasoning had been based however more upon majority's acceptance -- if everyone else is acting upon the assumptions of normality and independence, I thought, what good will there be adopting a new theory? Isn't finance more akin to social sciences than to natural sciences after all? It is these beliefs that Mandelbrot sets out to dispel with this monograph. He does so convincingly with great confidence and tenacity. The book consists of three parts, first the examination of the current theories (CAPM, MPT, Black-Scholes), next explanation of his methodology (fractal analysis), and finally of posing questions that should be answered (Mandelbrot asserts that virtually all the current theories should be reexamined under more realistic assumptions). To readers who have followed Mandelbrot's findings even remotely, there are no new advancements recorded in this book per se. He explains with concepts he developed throughout his entire career -- fractals; more specifically self-similarity, long-range dependence (via the Hurst exponent), and fractal decomposition of [trading] time. Mandelbrot's original research without doubt launched an entirely new field of study in science and engineering. Here his objective seems to be persuasion of the general public that an overhaul of existing methods is due. This may be evidenced by the absence of equations in the main text (some are included in the notes/appendix), and by the existence of the second author of this book. The book is also a trajectory of Mandelbrot's intellectual development. He explains, with characteristic detail, why, how, and when he has become interested in the problems as he did. The result is interesting accounts of historical figures (Bachelier, Hurst, Markowitz, etc) and records of encounters with eminent figures in mathematics and economics (Lévy, Poincaré, Sharpe, and Fama (his student) to name a few). There has long been a need for mathematical models that reflect the market more accurately. Should the new models be in form of incremental modifications of existing models or should they be based on an overhaul of the foundation as Mandelbrot proposes? Be prepared to be challenged, if not altogether persuaded, by Mandelbrot's arguments.