After graduate school, he took a job for a real estate company that did business with his parent's company, the Gap. The business was not successful and he became president of Pisces Inc., the Fisher family's investment management company. He established a relationship with Lewis Wolff to jointly purchase several Fairmont hotels in San Francisco which led to his investment in the Oakland Athletics. He also has stakes in Major League Soccer's San Jose Earthquakes and Scotland's Glasgow Celtic football club.
Fisher has been the A's majority owner since he and Wolff closed on their purchase of the team in 2005. However, Wolff is operating head of the franchise as managing partner.