For a 5-year investment portfolio, I've identified 40 stocks that I believe have a very bright future based on my research, and I plan to buy them using the dollar cost averaging (DCA) method. Let's say, in the best-case scenario, I expect each of these stocks to outperform the Nasdaq in terms of compound annual growth rate (CAGR) over the next five years. Scientific studies indicate that I'm "over-diversifying." In your opinion, what is the theoretical maximum number of stocks we should hold to achieve the best return?