Warren Buffett, known as the 'Oracle of Omaha,' is widely considered the most successful investor of the 20th century. Born during the Great Depression, he showed an early aptitude for business, buying his first stock at age 11 and filing his first tax return at age 13.

After studying under Benjamin Graham at Columbia Business School, Buffett returned to Omaha and began his investment partnerships. In 1965, he took control of Berkshire Hathaway, a struggling textile company, and transformed it into one of the world's most valuable conglomerates.

Buffett's investment philosophy evolved over time, influenced heavily by his partnership with Charlie Munger. He moved from Graham's 'cigar butt' approach—buying cheap, mediocre businesses—to focusing on wonderful businesses at fair prices.

His investment in American Express during the 1964 Salad Oil Scandal crisis exemplifies his approach: buying wonderful companies at fair prices when others are fearful. His stake, now worth over $25 billion, has been one of his most successful long-term holdings.

Buffett's annual letters to Berkshire shareholders are studied like scripture by investors worldwide. His clear thinking about business, investing, and capital allocation has influenced generations of investors and business leaders.