The topic of how many stocks you should hold is ambiguous. An old investing adage is 'concentration builds wealth', but is that true? I'm not so sure. It depends on the skill + experience of the investor and their conviction to hold the assets.
As a retail investor with less experience, I keep a diversified portfolio of stocks and index funds. I'm holding around 50 stocks and funds. Diversification lowers your risk and exposure to any given individual position. However, I do realize that concentration yields benefits like intricately focusing on the companies your money is riding with. Investing is an art steeped in allocation. When conviction (and profits) are high, I think it's acceptable to keep a higher allocation of such securities.