Beat The Street wrote:Once again, trust the largest sample size. It is quite easy to pick periods of outperformance for either fund. I could say since 2/8/2008 rzv is up 28% but vtsmx only 12%. The short term is always surprising, long term rarely is.
Unfortunately--not zinging you, just brooding about a REAL problem--investment thinking seems to be enormously damaged by the habit of averaging everything with equal weight between two sharp-cutoff endpoints. The devil is in the endpoints, and when it is not intentionally tendentious cherry-picking, it is best a source of endless controversy between intellectually honest seekers after truth.
Long term absolutely
can be surprising. "Boxcar averaging," which seems to be the normal procedure, is evil. Even a 10-year moving average is subject to vicious instability. It incorporates a upside-down echo of ten-year-old financial headlines. Furthermore, boxcar averaging actually
creates periodic cycles in the moving average that did not really exist in the data, just as a seashell manufacturers "the sound of the ocean" from ambient room noise.
The results you get for even an 75-year average are going to be meaningfully different depending on whether you start measuring from from June, 1929 or June, 1932. For example, the annualized total return of small-company stocks from June 1929 to August 2004 is 11677/1.578^(1/75) = 12.6%. From June, 1932 to June, 2007, 16983/0.175^(1/75) = 16.5%.
That's almost
a 4% difference in annualized return over 75 years, depending on choice of endpoints. Yet people will claim to see vital investing implications in long-term portfolio differences measured in basis points.
Worse yet, all theory based on long-term statistics is only useful if you, in fact, stay the course in a portfolio for the long term. But nobody actually does this. Very few ordinary mainstream investors, for example, were actually putting 20% or more of their stock portfolio into international stocks thirty years ago. And I'd guess very few are putting less than 20% into international today. Regardless of the reasons, the facts are that people do not restrict themselves to investments and indexes available thirty years ago. And, meanwhile, there are serious questions about the continuity of the sample. I mean, really, is the stock market the same thing today as it was before the creation of the SEC? Are mutual funds today the same as things as they were before the Investment Company Act of 1940.
Annual income twenty pounds, annual expenditure nineteen nineteen and six, result happiness; Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery.