He also invested in a shopping mall in Columbus, Ohio. He has talked about some of those who have helped him over the years in business: "I couldn't have learned about business without a parade of teachers guiding me... from Milton Friedman to Donald Trump... and now, Les Wexner and Warren Buffett. I even learned a thing or two from Planet Hollywood, such as when to get out! And I did!" He has significant ownership in <answer>Dimensional Fund Advisors</answer>, an investment firm. Schwarzenegger is also the owner of Arnold's Sports Festival, which he started in 1989 and is held annually in Columbus, Ohio. It is a festival that hosts thousands of international health and fitness professionals which has also expanded into a three-day expo. He also owns a movie production company called Oak Productions, Inc. and Fitness Publications, a joint publishing venture with Simon & Schuster.
What investment firm does Schwarzenegger maintain partial ownership of?
Dimensional Fund Advisors