Early in his career, Dr. Ari Kiev ran a suicide prevention hotline. These days the Cornell-trained psychiatrist is trying to keep people from hurting their P&Ls. An expert on the psychology of trading, Kiev is spending four days a week with traders at Greenwich, Connecticut-based SAC Capital Management, the highly successful and extremely secretive hedge fund group run by Steve Cohen. The hedge fund manager first took an interest in the doctor, who has also worked with U.S. Olympic athletes, after reading a 1992 article that Kiev had published in a fitness magazine. Kiev also works with equity traders at Salomon Smith Barney and at several other hedge funds. Now he's selling some of his secrets to the masses. In his latest book on trading psychology, Trading in the Zone: Maximizing Performance with Focus and Discipline, Kiev explains how the best traders are able to mentally shut out distractions, diminishing the chances of error through poor judgment - as top athletes do before competitions. The book's back cover features several promotional blurbs from hedge fund managers and Wall Street traders, but the author emphasizes that his work is not just about stocks and bonds. "I try to get traders to focus on what they've done right, not on all the things that potentially could go wrong," says Kiev. "This is about life, not just trading."