Nancy Zimmerman is comanaging partner at Boston-based hedge fund Bracebridge Capital. With more than $10 billion in assets under management, it is one of the world's largest hedge funds with a woman at the top. She got her start buying currency options on the floor of the Chicago Mercantile Exchange. She cofounded Bracebridge in 1994 after running the interest rate options group at Goldman Sachs. Zimmerman serves as a trustee at Brown University, her alma mater.