Farnum is a Managing Partner at New Summit Investments. Farnum is also the Chief Strategist at Arjuna Capital, which he co-founded in 2013.

Farnum established one of the earliest sustainable investment firms in the country, Advent Advisors, in 1987. Prior to launching Arjuna Capital, Farnum served for 19 years as Senior Vice President, Chief Strategist, and Technical Analyst at Trillium Asset Management, a pioneer in responsible investing.

In 2007, Farnum founded the nonprofit Open Media and Information Company Initiative, a shareholder coalition promoting an open, competitive digital ecosystem. His work with OpenMIC pioneered shareholder activism on issues such as net neutrality and online privacy. Farnum has an extensive clientele in the music and film industries, working with many of the leading progressive voices in the entertainment world.

He has served on the Boards of the Future of Music Coalition, the Public Media Company, the Nasher Museum, Duke Performances, and the Art of Cool Project. He received his bachelors, masters, and doctoral degrees in philosophy from the University of North Carolina at Chapel Hill.