What's the difference between theme funds and index funds? Theme fund is a kind of fund that focuses on a certain industry theme. The investment direction of such funds is to make stock selection criteria based on a certain factor of an industry, and finally make portfolio investment, such as science and technology theme funds and pharmaceutical theme funds. Index funds take a specific index as the target, take the constituent stocks of the index as the investment object, build a portfolio by buying all or part of the constituent stocks of the index, and track the performance of the target index. The essential difference between the two is that the scope of index funds is wider, with the aim of keeping up with the index, while the scope of theme funds is narrower, with the aim of outperforming the index.