I support a particular hospital charity that each year or so runs a home lottery and every year I enter. To date I have won a digital camera, an iPod, an Apple TV, a tonne of chocolate, wine (brilliant for a non drinker but good for presents) and a host of other goodies. In fact I have never had a time when I have entered and not won something. Whilst my expectancy is not quite positive its not bad. If I were a newsagency that sold lottery tickets and I had this many winning entries bought via my store people would be clambering over me thinking there was something special about my store. One of the things we ignore in life is that we are subject to the same harsh statistics as everyone else – we have what I call the myth of individual specialness. Our basic narcisssim leads us to believe that the laws that apply to the universe don’t really apply to us, as a result we spend a lot of time fooling ourselves into think there is something special or magical about what we do.
My capacity to win this particular lottery has nothing to do with me other than the fact that I enter, I am simply subject to the laws of large numbers as is everyone else. If you get enough people doing the same thing over a long period time then the probable drifts into the realm of the inevitable. It is no wonder some people win the lottery twice. But because we are such poor natural statisticians this seems like magic to us and we ascribe some special quality to ourselves and this is apparently a well known phenomena in both lottery winners and those who have inherited wealth. They believe that something divine about themselves means that they were meant to win – they cannot accept that it was blind luck. My wife has a friend who received a very large inheritance from her parents, she has now divorced herself from all her friends of many decades because she believes that there is something superior about herself other than being the lucky product of the sperm sprint derby that we all undergo. Sometimes you land in the right spot and sometimes you dont.
The central issue here is that even in trading we are subject to the ruthlessness of statistics and this ruthlessness is often at odds with our own emotional endurance. For example if you have a system with a positive expectancy this means that on average and over time your system will make money. But note there are two presumptive phrases involved in this definition – on average and over time. You need to have the resilience to ride out the times when the system is not making money. When traders first encounter the notion of expectancy they assume that is means that every trade they take will make $X and are surprised when this does not happen. All trading systems will experience runs of losses, this is the natural order of things and you can experiment with this for yourself by looking at a coin toss simulator. If you click here you can see how streaks of either heads or tails form – this is a good example of what can happen in trading systems.
Despite trading being a basic exercise in statistics at its core it is an exercise in resilience because we have to find ways of dealing with brutality of statistics and even when we know our system is sound it is still hard to take a continual series of losses. Inevitably we come back to the notion of courage as a central tenet in the success of any trader.
Yep – I agree Chris. People don’t understand sample size. Also reminds me of this (old but still relevant) TED talk (3min)…
https://www.ted.com/talks/arthur_benjamin_s_formula_for_changing_math_education#t-11310