Last week, I had the opportunity to attend the 2010 Morningstar Investment Conference.
During a panel conversation with four top Morningstar researchers, the moderator asked a question about the studies that are done from time to time, which tend to show that Morningstar’s star ratings don’t work all that well as predictors of future performance.
Don Phillips, President of Fund Research at Morningstar, had a great reply:
“The star rating is a grade on past performance. It’s an achievement test, not an aptitude test…We never claim that they predict the future.”
Pretty straightforward answer, no? The star ratings aren’t even intended to predict future performance. They’re simply a calculation based on how each fund’s risk-adjusted return has compared to that of its peers (with a very heavy emphasis on the most recent 3 years of performance).
That, combined with the fact that there are more successful predictors of performance available (i.e., expense ratios), leads to one obvious conclusion: Don’t base your fund picks on how many stars they have.
It also leaves me with a question: What good are the star ratings if they’re not useful for picking funds?