This discussion is mostly irrelevant in practice, since the two funds track each other extremely well.
Even if it’s true that the S&P500 has beaten the overall market in the past, I doubt it’s statistically significant. Theoretically I can’t imagine a good reason why the optimal investment answer would be “pick roughly the top 500 companies, but not exactly those, but something like that picked by a committee of people you don’t know, in proportion to their market cap.” VTSAX just seems simpler as it tries to approximate “pick every company in proportion to their market cap.” This is also what the one mutual fund theorem in portfolio theory says one should do (if one limits oneself to US stocks only), so it has solid theoretical basis, unlike the S&P500.
This discussion is mostly irrelevant in practice, since the two funds track each other extremely well.
Even if it’s true that the S&P500 has beaten the overall market in the past, I doubt it’s statistically significant. Theoretically I can’t imagine a good reason why the optimal investment answer would be “pick roughly the top 500 companies, but not exactly those, but something like that picked by a committee of people you don’t know, in proportion to their market cap.” VTSAX just seems simpler as it tries to approximate “pick every company in proportion to their market cap.” This is also what the one mutual fund theorem in portfolio theory says one should do (if one limits oneself to US stocks only), so it has solid theoretical basis, unlike the S&P500.
I didn’t know this, now it makes much more sense, thank you.