The son of a wholesale grocer, he grew up in Fort Worth, Texas

Fort Worth, Texas

Fort Worth is the 16th-largest city in the United States of America and the fifth-largest city in the state of Texas. Located in North Central Texas, just southeast of the Texas Panhandle, the city is a cultural gateway into the American West and covers nearly in Tarrant, Parker, Denton, and...

. He graduated from the University of Texas with a degree in mathematics, where he was a member of the Tau chapter of the Kappa Sigma

Kappa Sigma

Kappa Sigma , commonly nicknamed Kappa Sig, is an international fraternity with currently 282 active chapters and colonies in North America. Kappa Sigma has initiated more than 240,000 men on college campuses throughout the United States and Canada. Today, the Fraternity has over 175,000 living...

 fraternity

Fraternity

A fraternity is a brotherhood, though the term usually connotes a distinct or formal organization. An organization referred to as a fraternity may be a:*Secret society*Chivalric order*Benefit society*Friendly society*Social club*Trade union...

. He was recognized by the national organization in 1996 as Kappa Sigma Man of the Year. He then went on to earn his MBA from Stanford Business School.
After business school, Rainwater landed a job as an investment banker, but soon accepted an invitation from former Stanford classmate Sid Bass

Sid Bass

Sid Richardson Bass is an American investor and businessman.-Life:He is a graduate of Yale University and Stanford Business School. His father, Perry Richardson Bass , built an oil fortune with uncle, Sid Richardson . Bass took control of the business in 1968. His investments include oil and gas...

 to manage and diversify the Bass family portfolio.