Are specialists ‘special’? We answer this question using data on the stock portfolios of U.S. institutional investors for the period 1990-2014. Our main findings are as follows: first, we show that many investors tend to focus their economically meaningful investments on a relatively small subset of stocks. This translates itself into a strong and significant portfolio overlap. Finally, specialized investors (those with concentrated portfolios) tend to emphasize certain stock-specific characteristics, but we find no evidence that their returns are significantly different from those of diversified investors. Overall, our findings suggest that specialists are not that special.