Our History

Investment Philosophy Inspired By Legendary Value Investors

Prospector Partners began in 1997 when John Gillespie reunited with his mentor, Jack Byrne, who became a founding investor of Prospector. Byrne was the legendary CEO of GEICO (acquired by Berkshire Hathaway), Fireman’s Fund (acquired by AIG), and White Mountains Insurance Group. Warren Buffett referred to Jack Byrne as “the Babe Ruth of insurance.”

John Gillespie began his career working directly for Byrne as a Senior Financial Analyst at GEICO. In addition to Byrne’s investment with Prospector, he also hired Prospector to manage capital for White Mountains Insurance Company where Gillespie served as a Director from 1999 to 2015.

Prospector portfolio managers Kevin O’Brien, who was a Managing Director for White Mountains Advisers, and Jason Kish both played prominent roles in managing investments for White Mountains.

Much of the investment philosophy at Prospector is inspired by the value investing principles of Jack Byrne and Warren Buffett*.

*Prospector Partners is not affiliated with Warren Buffett or Berkshire Hathaway.