Patricia C. Dunn rose from a secretary to lead Barclays Global Investors and then serve as chairwoman of Hewlett-Packard only to have her career eclipsed by her involvement in an attempt to stop boardroom leaks by spying on directors, journalists and employees, Patricia Cecile Dunn was born on March 27, 1953, in Burbank, Calif., the daughter of a vaudeville actor and a Las Vegas showgirl. Her father died of a heart attack while she was still a girl. The family then moved to Marin County, north of San Francisco. Her mother later died of breast cancer. Ms. Dunn attended the University of Oregon before transferring to the University of California, Berkeley, where she graduated in 1975 with a degree in journalism. After briefly working for a community newspaper in San Francisco, she was hired as a secretary for Wells Fargo Investment Advisers (which became Barclays Global), then rose through the ranks as she earned a reputation as an ace saleswoman. She was among the first women to run a large investment management company in the United States, and she introduced an index fund and other computer-intensive quantitative investment management techniques in wide use today. Her most important accomplishment there was the creation of Exchange-Traded Funds, which despite initial resistance from the firm’s corporate parent became a highly lucrative product. E.T.F.’s are a basket of stocks that reflect the industry category or an index. Besides William Jahnke, her husband of 30 years and the former chief executive of Wells Fargo Investment Advisers, Ms. Dunn is survived by their two daughters, Janai Brengman and Michelle Cox; a son, Michael Jahnke; a brother, Paul Dunn; a sister, Debbie Lammers; and 10 grandchildren.