To: 2sigma who wrote (61700 ) 11/1/2000 3:05:50 PM From: KymarFye Respond to of 99985 OT, FYI: The chart that our unfriendly friend was referring to is constructed as follows: The left or y-axis side of the graph is constructed from negative to positive, and represents the amount ahead or behind you would be in a coin toss game (i.e., correct guess: add one, wrong guess: subtract one). The x-axis or bottom line of the graph represents the number of tosses. If you were to toss a coin 100 times, the result would, indeed, very likely look on first glance like many stock charts, rising and falling, with apparent "uptrends" and "downtrends," pullbacks and snapbacks, and so on, that were really just the result of random processes (winning streaks, losing streaks, flat periods, etc.). In my opinion, the resemblance between the graph (whose like can be found in the works of Ralph Vince, among others) and the price action of a stock is not entirely coincidental - as the price action of a stock is, in a way, nothing more or less than the record of numerous modified "coin tosses." There is also more than a kernel of truth in Mr. A's offensively, presumptuously, and exaggeratedly couched posts. It is well-known that many if not most traders are operating in a manner which, if analyzed rigorously, would demonstrate a very high likelihood, approaching mathematical certainty, that they will end up ruining their trading accounts or worse, and I do not doubt that Mr. A is still congratulating himself for having delivered this lesson with enough drama to scare sense into ignorant sods like us. The example given on this board, for instance, of a trading strategy that allowed one trader to maximize a small investment, lose it all, then start over is in this sense quite typical of what mathematical analysis of common trading methods predicts. Quite often, if not quite invariably, the same strategies that allow for quick appreciation of outsized profits also include the potential for outsized (i.e., ruinous) losses. It is worth noting, however, that SOME such systems (the "Turtle" system is probably the most famous) have been traded effectively for many years, and there are more than a few that claim, to my mind rather persuasively, to offer a "positive mathematical expectation."