In 1929 Jesse Livermore's fortunes were at their zenith. He had made a profit of $100 million dollars shorting the markets during the great crash. Yet, by 1934, he was bankrupt. In just five short years one of the greatest stock-traders the world has known lost his entire $100 million fortune. We cannot blame this on inadequate trading rules - they were fully formulated by then. We must conclude that he ignored at least one of his sacrosanct rules - never to hold on to a losing position. If Livermore did hold losing positions until his $100 million fortune was wiped out - in spite of the lessons of 41 years of trading - we must presume his mental processes had malfunctioned, due either to stress, depression, or a combination of the two.