Duggan is an investor who acquires and sells companies in diverse sectors including robotic surgery and billboards. He sold drugmaker Pharmacyclics in 2015, realizing a personal gain of more than $3 billion. Duggan's the largest shareholder in Summit Therapeutics, a biopharmaceutical oncology company.
The majority of Duggan's fortune is derived from his stake in Summit Therapeutics, a biopharmaceutical company. Duggan owns about 75% of the stock, according to a January 2025 filing with the US Securities and Exchange Commission.
He has a long career as an investor and his other holdings include a 79% stake in Pulse Biosciences, according to a December 2024 Form 4 filing.
The value of Duggan's cash investments is based on an analysis of dividends, insider transactions, taxes and market performance, and incorporates proceeds from other deals. These include the sale of Pharmacyclics to AbbVie in 2015, which provided Duggan more than $3 billion.
Representatives for Summit didn't reply to requests for comment.
Robert W. "Bob" Duggan has been investing since he was a student at the University of California, Santa Barbara in the mid-1960s. The Berkeley, California-born billionaire said in a 2010 address to UC Santa Barbara graduates that he made money in college by investing in ethernet companies.
In 1976, he and then-brother-in-law Dan Patterson started Cookie Muncher's Paradise, a bakery they expanded to 16 locations as a gourmet sandwich chain called Paradise Bakery. They sold it in 1987 for about $6 million.
Duggan acquired in 1980 a majority stake in ethernet company Communication Machinery. He sold it in 1988 to Rockwell International for $40 million. From 1986 to 1994, Duggan was a board member -- including a stint as chairman -- of Government Technology Services, a large vendor to the federal government.
According to his biography on the website of UC Santa Barbara, Duggan became chairman and CEO of Computer Motion, a robotic surgery company, in 1990. Three years later, Computer Motion became the first company to have a robotic surgery system approved for use by the Food & Drug Administration, according to company filings with the U.S. Securities and Exchange Commission. In 2003, it was sold to Intuitive Surgical for $67 million in stock. Duggan later sold his stake for more than $150 million, according to regulatory filings.
In 2004, Duggan began amassing a stake in Pharmacyclics, becoming chairman and CEO in 2008. The company struck a $975 million deal in 2011 with a subsidiary of Johnson & Johnson to fund drug development in exchange for a split of the profits of a drug that could treat certain lymphomas and multiple myeloma.
Duggan became a billionaire in 2013 on the back of a surging share price at Pharmacyclics. In 2015, Pharmacyclics was sold to AbbVie for $21 billion in cash and stock. Duggan founded Duggan Investments, a venture capital firm, in the same year.
He joined the board of directors at Summit Therapeutics, a biopharmaceutical company, in 2019 and became the chief executive in 2020.