Image Warren Buffett, about age 2. Credit... Courtesy of the Susie Buffett Collection

The superhuman tenacity that he brought to sniffing out undervalued companies also served him well in his personal life. Unable to win the interest of Susan Thompson, he chased her father instead; eventually, she became Susie Buffett. They had three children, to whom a distant yet manipulative Dad was “the disengaged, silent presence, feet up in his stringy bathrobe, eyes fixed on The Wall Street Journal at the breakfast table.” But Dad was putting his research to amazingly lucrative use. Only when Susie accidentally put dividend checks down an incinerator and scurried to retrieve them did she realize how much money her husband was making.

“The Snowball” (with a title that refers to Mr. Buffet’s way of making things get bigger and bigger) tracks his financial coups without becoming a string of “and then he bought ...” stories. Part of the book’s liveliness comes from the feisty, penny-pinching characters with whom Mr. Buffett liked to lock horns. The story of Mr. Buffett’s business rise is also a social climb of sorts, despite his cultivated folksy air. The book details his eyebrow-raising friendship with Katharine Graham of The Washington Post, an anomalous liaison since he claims that Daisy Mae of the “Li’l Abner” comics was his feminine ideal. In any case, Mr. Buffett required a constant supply of hamburgers and motherly care. He surrounded himself with Susie, a surrogate wife (Astrid Menks, whom he later married) and a close circle of other women.

One of many priceless anecdotes here involves another Buffett female friend who happened to stay in Ms. Graham’s guest room. When this friend called, shocked, to tell Mr. Buffett that there was a real Picasso in the bathroom, he replied that he had stayed in that guest room for years and never noticed it. What he noticed was that the bathroom contained free shampoo.

“The Snowball” features equally good stories about power players, including Akio Morita, a co-founder of Sony, and Bill Gates, whom Mr. Buffett instantly recognized as a soul mate. There are many tales of triumph, like the one about how The Omaha Sun, while controlled by Mr. Buffett, blew the lid off fiscal improprieties at Father Flanagan’s pious Boys Town. Then there are the business stories that make it shockingly timely. Ms. Schroeder reports in depth on Mr. Buffett’s reluctant involvement in the 1991 near-meltdown of Salomon Brothers with lessons on the risks of deregulation, the precariousness of derivatives and the dangers of involving government in bailing out financial institutions.

In shaping its definitive portrait of Mr. Buffett, “The Snowball” need not make excessive claims of his importance. With story after story, Ms. Schroeder makes that self-evident. “No group of shareholders in history,” she writes, with one eye on her subject’s life history and the other on his legacy, “had ever missed their C.E.O. as much as Berkshire’s shareholders would miss Buffett when he was finally gone.”