How A Chicago Accountant Quietly Built A Billion-Dollar Fortune Amassing Humdrum Businesses

Chicago dealmaker Larry Geis built a $6 billion fortune by buying and scaling dull industrial businesses.

Madison Industries’ long-running roll-up strategy turned niche acquisitions into a major platform, including Madison Air.

A $2.2 billion IPO for Madison Air and multibillion-dollar sales of filtration and fire-safety units highlighted the value created.

The story underscores how buy-and-build strategies in boring industrial niches can generate major public-market exits and returns.