Tuesday, July 11, 2006

Classifying investment decisions

I recently read an article by James Montier, who wrote "Behavioral Finance - Insights into Irrational Minds and Markets." He suggested classifying investment mistakes into 4 categories based on two axes:

Good outcomeBad outcome
Right reasonSkillBad luck
Wrong reasonGood luckMistake

Thinking about the decisions that I've recorded here, I can see that all of the individual stock purchases and the single sell have been very good outcomes. In fact all of my positions are beating the S&P 500 index and all but one (Berkshire Hathaway) have annualized returns better than 15%. Looking over the reasons I documented for those decisions, I think I can label my success as mostly skill. I focused on fundamentals and the fundamentals of each company have been good and improving.

The mutual fund investments I've made in my 401(k) had mostly good outcomes. I spent way too much time distrusting active funds (by stayin nearly 100% invested in an index fund) and I picked a poor time to become a bond investor. In the first case, I think I made a mistake by focusing too much on fees. In the second case, I think I've had a bit of bad luck.

But it's a lot harder to evaluate the decisions that haven't resulted in purchases or sells. It's a bit harder to analyze "sins of ommission" at least in part because they don't tend to leave traces in our memory. On the other hand, as Warren Buffett says, there are no called strikes in investing. It's entirely possible I would have made more money by purchasing my half-thought out or rejected ideas. But I'm not sure I would be as comfortable with them.

1 comment:

Mike Prosper said...

Hey Jon,

By complete accident, I found this page of yours - I also found that "secret" url you left on my laptop. :)

I had no idea you were so interested (and knowledgeable) in investments! You certainly seem to know what you're talking about. Half the time I don't know what the heck you're saying. We should talk sometime. I have some extra money I'd like to invest in individual stocks somewhere, but don't know where to start.