High Probability Trading - The "Coin Flip" Study

http://optionalpha.com - Today we'll cover a very common yet misunderstood concept when it comes to investing and high probability trading with options. ================== Listen to our #1 rated investing podcast on iTunes: http://optionalpha.com/podcast ================== Download a free copy of the "The Ultimate Options Strategy Guide": http://optionalpha.com/ebook ================== Still working a day job? Then our "Take 5" segment is for you. 5 mins videos each day on 1 thing you can apply trading options: http://www.youtube.com/playlist?list=PLhKnvfWKsu40z0EnsX0TNqCgUzb8tmM04 ================== Start our 4-part video course (HINT: these videos are NOT posted anywhere else online): http://optionalpha.com/free-options-trading-course ================== Just getting started or new to options trading? Here's a quick resource page we made that you'll love: http://optionalpha.com/start-here ================== Register for one of our 5-star reviewed webinars: http://optionalpha.com/webinars ================== - Kirk & The Option Alpha Team

Comments

1. +Option Alpha so it's important to have many trades so the probabilities roll out in time BUT why would anybody assume that the distribution of market prices is normal since it isn't, markets do not follow such a pattern or nor that they are efficient - clearly there are anomalies , fat tails, highly unlikely sigma-s occurring, well, quite frequently. I'm not sure the OTM probabilities for example are realistic in the long run but they seem to be a nice approximation. Let’s take a look at long term chart of SP500, is that the effect of normal distribution or does anybody notice a clear pattern of rising prices?
2. So many people get very confused with probabilities. Those with no formal education in the subject can get definitely confused. But even those with a formal education in the subject easily can get off track.
    One area of confusion I see often is people thinking that processes, such as stock movement, follow probabilites, instead of probabilities describing processes. Probabilities are just mathematical descriptions based on past history and other considerations. The processes themselves know nothing about the probabilities. They don't know when you had started counting your sequence, for instance. They have no memory.
    How about the so-called gambler's paradox. A gambler is watching a roulette wheel and notices that it has landed on black ten times in a row. He knows that the odds are 50/50 (ignoring "0" and "00" for the moment) between landing on a black or a red for each individual spin. He also know that the probability of getting ten blacks in a row is 1/1024 (2 to the tenth power is 1024); that is, virtually zero. So he thinks that FOR SURE the next spin has to be a red since the chances of NOT getting a red in 11 spins is virtually zero.
    What the gambler has forgotten (or, more likely simply ignorant of) is that the roulette wheel has no memory. For each individual spin the chances are 50/50 between red and black regardless of the recent past.
    So even though it is true that BEFORE THE 11 SPINS there is an exact probability of 1/2048 that in 11 spins of a roulette wheel you would get 11 blacks in a row, once the first ten have occurred and you notice all blacks, you cannot say anything about the next spin other than that there's a 50/50 chance for either black or red--just like all the other spins. Again, the roulette wheel has no memory of what has occurred prior.
    The same is true with stock market probabilities. Even if they were exact like the roulette wheel (and stock market probabilites are surely not exact), you can use them only as guides into the future for a particular time range. But once the stock movement has started to occur, you need to at the very least recalculate the probabilities for whatever range of time is still of interest to you. If the stock hasn't moved as much as it was "supposed to" have during the initial part of the time range, you cannot assume it will "make it up" in the latter part. If you think this, you are falling victim to a version of the gambler's paradox.
    One more thing: Along the lines of what I just said, I've seen traders completely misuse probabilities and standard deviations when attempting to make correct market decisions. I once read a pseudo-scientific article written by someone whom I believe was sincere. But ... oh so how misguided! His system went something like this. Throughout the trading day he constructs a bell-shaped (normal) curve of a stock based on its intraday movements. If a majority of the bell curve seems to be being built on either the left or the right side of the bell, he says there is a great chance that the rest of the bell "has to be" built on the opposite side. Thus, he would use this "knowledge" to day trade the latter half of the trading day.
    The errors in his thinking are numerous. One of the errors, of course, is that the stock movement doesn't "know" its on someone's left- or right-side of a bell. Indeed, if he had instead constructed a bell in real time with a total time range of only the first half of the day (instead of the full day), he would have ended up with a completely different bell that is is "filled in" on both sides. Everything about his method is arbitrary including the time range. There are an infinite number of time ranges and an infinite number of possible histogram bin possibilities when constructing your histogram. Yet he swore by this "scientific" system. Lots of ignorance abounds.
3. Hi Kirk. Question - I am quite new to this but I was wondering if you are exercising your option (actually buying the stock) or selling your option at a higher premium once you hit your strike price? I'm a little confused on this aspect and have only found videos showing that side of options trading. Thanks 
4. The most common but misunderstood principle of investing = The "Coin Flip" Study - watch it now here: http://buff.ly/1k39AsN