Warren Buffett is an American investor, business magnate, and philanthropist, serving as chairman and CEO of Berkshire Hathaway since 1970. Renowned for his disciplined value investing strategy, Buffett has built Berkshire into a diversified conglomerate with holdings in insurance, energy, manufacturing, and consumer goods. Often called the 'Oracle of Omaha,' he is widely regarded as one of the most successful investors in history and has pledged much of his wealth to charitable causes.