T homas Bailey is a self-made American billionaire who is the founder of the mutual fund company, Janus Capital Group. He founded the company in 1969 and built it into one of the largest and most successful mutual fund companies in the United States, with a particular focus on growth stock investing. During the 1990s dot-com boom, Janus became a massive powerhouse, with its funds' heavy concentration in high-flying technology stocks generating spectacular returns and attracting a huge influx of assets from investors.

However, the company was also severely impacted when the dot-com bubble burst in 2000, leading to massive losses for its funds and a decline in its fortunes. Bailey retired as the CEO of the company in 2002. His vast fortune was made through his founding stake in the company he built into a major force in the asset management industry. He has since focused on his passion for ranching and owns a large cattle ranch in Colorado. He is also a prominent philanthropist.