Unfortunately, the results of this new analysis are not what I was expecting. The author, Daniel Fricke, of "Are Specialists "Special"? The Case of Institutional Investors" draws two conclusions from his analysis. First, there is a significant amount of overall with portfolios even by those who are specialists. Everyone concentrates on the same stocks. Second, the specialists who concentrate their portfolios do no better than those who are diversifiers. The hypotheses that those who have information advantage or skill will have more unique portfolios and generate extra returns is rejected. This is with a more general dataset and may not fully take advantage of the dynamic nature of trading, but it suggests that skill is hard to find.
There are investors who think they are smart and unique but end up at the same place as diversifiers. The investment theme of having a few eggs in your basket and watching them carefully does not seem to apply.