Offer your thoughts or opinion on the input financial query or topic using your financial background.

What evidence or research suggests that mid- or small-capitalization stocks should perform better than large caps?
Efficient Frontier has an article from years ago about the small-cap and value premiums out there that would be worth noting here using the Fama and French data. Eugene Fama and Kenneth French (F/F) have shown that one can explain   almost all of the returns of equity portfolios based on only three   factors: market exposure, market capitalization (size), and   price-to-book (value). Wikipedia link to the factor model which was the result of the F/F research.