The Little Book of Common Sense Investing, written by John C. Bogle, is a finance book that advocates for a simple and low-cost approach to investing. Bogle, the founder of Vanguard Group, explains the benefits of index funds and passive investing. He argues that trying to beat the market through active trading is a losing game and that investors should focus on long-term, diversified investments. This book provides practical advice on how to build a low-cost portfolio and achieve market returns. It is a must-read for anyone looking to understand the fundamentals of investing and build a solid investment strategy.