Question: Which American television drama series stars Paul Giamatti and features Sean Ringgold?
Sentence (from "Billions (TV series)"): The series is loosely based on the activities of crusading federal prosecutor of financial crimes Preet Bharara, the former U.S. Attorney for the Southern District of New York, and his legal battles with hedge fund manager Steve Cohen of S.A.C. Capital Advisors.
Relevant evidence: No