Résumé de One Up on Wall Street

Peter Lynch’s "One Up on Wall Street," first published in 1989 and co-written with John Rothchild, argues that ordinary individual investors can outperform professional money managers by exploiting everyday observation and local knowledge. Lynch, who ran Fidelity’s Magellan Fund from 1977 to 1990, builds the book around his conviction that amateurs hold an edge precisely because they encounter products, services, and trends before Wall Street analysts notice them—the “invest in what you know” principle. The book is organized into three broad sections. The first dismantles the efficient-market orthodoxy and the notion that professionals always win, detailing the structural handicaps institutions face, such as bureaucracy, diversification mandates, and career risk. The second is the practical core: Lynch’s classification of companies into six categories—slow growers, stalwarts, fast growers, cyclicals, turnarounds, and asset plays—each demanding different expectations and exit rules. Here he also presents his famous ratio, the PEG (price-to-earnings ratio divided by earnings growth rate), along with guidance on studying annual reports, cash positions, inventories, and insider buying. The third section lays out Lynch’s “tenbagger” hunt and his rules for buying and selling, including his preference for dull, unglamorous names, his avoidance of “whisper stocks,” and his caution against “diworsification.” Throughout, he draws on his own mistakes and successes at Magellan, including holdings he researched by simply using the products. The result is a bottom-up, research-driven manual for stock picking rather than a macro-forecasting tract—one that remains a standard reference in the money and finance genre.