Jack Welch

Jack Welch transformed General Electric from a sleepy conglomerate into a $410 billion market-cap giant over 20 years—a 34-fold increase. He pioneered Six Sigma, saving GE an estimated $12 billion in its first five years, and implemented the rank-and-yank system that boosted productivity 5% annually. Under his tenure, GE’s revenues rose from $26.8 billion to $130 billion, and earnings per share grew 13% per year. His authoritarian warmth balanced pressure with mentorship, though critics note the post-2001 decline. Still, no other CEO on this list matched his 20-year shareholder return of 4,000%.