Louis Loss (June 11, 1914 – December 13, 1997), William Nelson Cromwell Professor of Law, Emeritus at Harvard Law School, was a legal scholar considered by many to be the intellectual father of modern securities law. He is best known for his treatise Securities Regulation, which is still considered to be the definitive authority on the subject and which has been cited over 50 times by the Supreme Court of the United States. The Oxford English Dictionary credits him with having coined the word tippee, to refer to someone who trades stock after getting a tip from a corporate insider.