That is how I came back to Wall Street for a third attempt. I had been studying, of course, trying to locate the exact trouble with my system that had been responsible for my defeats in A. R. Fullerton & Co.’s office. I was twenty when I made my first ten thousand, and I lost that. But I knew how and why--because I traded out of season all the time; because when I couldn’t play according to my system, which was based on study and experience, I went in and gambled. I hoped to win, instead of knowing that I ought to win on form. When I was about twenty-two I ran up my stake to fifty thousand dollars; I lost it on May ninth. But I knew exactly why and how. It was the laggard tape and the unprecedented violence of the movements that awful day. But I didn’t know why I had lost after my return from St. Louis or after the May ninth panic. I had theories--that is, remedies for some of the faults that I thought I found in my play. But I needed actual practice. There is nothing like losing all you have in the world for teaching you what not to do. And when you know what not to do in order not to lose money, you begin to learn what to do in order to win. Did you get that? _You begin to learn!_ _V_ The average ticker hound--or, as they used to call him, tape-worm--goes wrong, I suspect, as much from over-specialization as from anything else. It means a highly expensive inelasticity. After all, the game of speculation isn’t all mathematics or set rules, however rigid the main laws may be. Even in my tape reading something enters that is more than mere arithmetic. There is what I call the behavior of a stock, actions that enable you to judge whether or not it is going to proceed in accordance with the precedents that your observation has noted. If a stock doesn’t act right don’t touch it; because, being unable to tell precisely what is wrong, you cannot tell which way it is going. No diagnosis, no prognosis. No prognosis, no profit.