
With data back to 1935, the US market has never achieved anywhere near the current level of concentration in top market cap companies.
What caught my eye was the reader comments in the Wall Street Journal article. I saw a whole lot of "How's that working out for you?" and "Those stocks are cheap for a reason."
If we assume by default that markets are efficient, then all stocks should be equally attractive at current prices. But people only love the winners.
After lagging in previous years, the IWM small-cap ETF is unch ytd while large-caps are +7%. I'm on the hunt to buy IWM or a similar product, but I need a pullback. I don't want to buy into the rally.
Interestingly, this is only a US phenomenon. Internationally, there hasn't been much performance difference between large and small caps. That's based on a comparison of VEU and VSS.