W. R. Berkley Corp
A global commercial-lines insurer that writes specialty coverage through roughly 60 decentralized, niche-focused businesses, from excess-and-surplus lines and environmental insurance to reinsurance and accident-and-health policies. It began in 1967 when Harvard Business School student William R. Berkley and a classmate started an investment firm called Berkley Dean & Company out of a campus apartment, later steering it into insurance. The company is named for its founder, who began investing his lawn-mowing earnings in the stock market at age twelve.
Estimated from filings — the split-adjusted price range over the quarters each manager built the position. A range, not a fill price; 13F reports a quarter-end snapshot, not a trade date.