In this blog, I sometimes try to point out the similarities between stock trading and spam fighting. I happen to trade stocks (but never take tips I receive by email, not even in The Motley Fool) and I find that the two activities have things in common.
In trading, their are two types: discretionary trading and system trading. System trading follows a mechanical system (trading based on indicators, fundamental criteria, etc) whereas discretionary trading has an element of subjectivity. While system trading is based on mechanical signals it is still a reflection of the designer of the system.
The debate that comes up is whether or not a computer can trade better than a human can. As a trader, I make use of technical patterns and I have read some books that I believe gives my system an edge. I use many of the classic technical patterns, but I am aware that many of them don't work that well. I also started learning some new techniques that are based upon reversal patterns (swing trading - buying on weakness and selling on strength). These are all patterns that have a great deal of subjective elements built in; I trade based on looking at a chart and viewing the trend.
The question in the trading community is whether or not a computer can find better patterns than a human can. Can a computer find correlative elements to make trading profitable? The big problem with the stock market is that the market is made up of millions of people. For a computer to find an underlying order in the market would mean it would have to organize and predict human behaviour - not an easy task. Perhaps a Bayesian stock picking service is in order. Still, the concept is intriguing. Perhaps sometime in the future computers will do all the trading and put guys like me out of business.
But that leads me to spam fighting. Can a computer fight spam better than a human can? Can a computer learn to determine what is spam and what is not? Right now, humans are the ones that ultimately classify spam and computers mimic that behaviour by classifying subsequent messages that share elements of the pre-classified spam. However, afaik, a computer never classifies a message it has never seen before. In my next post, I'm going to examine whether or not a computer could ever learn to recognize spam the way a human could.