This book is about personal finance and investing and is written by Nick Maggiulli, a popular finance blogger. The book aims to provide data-driven answers to the biggest questions in personal finance and investing, such as why you need to save less than you think, why saving up cash to buy market dips isn't a good idea, and how to survive and thrive during a market crash. The book's main message is to advocate for a long-term, data-driven approach to building wealth, which the author calls "Just Keep Buying."