Passage: Christopher Paul Gardner (born February 9, 1954) is an American businessman, investor, stockbroker, motivational speaker, author, and philanthropist who, during the early 1980s, struggled with homelessness while raising his toddler son, Christopher Gardner Jr. Gardner's book of memoirs, The Pursuit of Happyness, was published in May 2006. The 2006 motion picture The Pursuit of Happyness, directed by Gabriele Muccino and starring Will Smith is based on the book.

Question: what does Paul Gardner do?
American businessman, investor, stockbroker