FYI: One of the reasons why so many mutual funds fail to beat their benchmark is because so many stocks fail to beat their benchmark. This idea has been pushed forward with papers like The Agony & The Ecstasy: The Risks and Rewards of a Concentrated Stock Position and Do Stocks Outperform Treasury Bills?
Vanguard recently came out with a piece that provides investors with additional data to bring to this conversation.
Regards,
Ted
https://theirrelevantinvestor.com/2019/03/25/how-concentration-affects-portfolio-performance/