Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

What evidence or research suggests that mid- or small-capitalization stocks should perform better than large caps?
I think it's safe to say that Apple cannot grow in value in the next 20 years as fast as it did in the prior 20. It rose 100 fold to a current 730B valuation. 73 trillion dollars is nearly half the value of all wealth in the world.  Unfortunately, for every Apple, there are dozens of small companies that don't survive. Long term it appears the smaller cap stocks should beat large ones over the very long term if only for the fact that large companies can't maintain that level of growth indefinitely.  A non-tech example - Coke has a 174B market cap with 46B in annual sales. A small beverage company can have $10M in sales, and grow those sales 20-25%/year for 2 decades before hitting even $1B in sales. When you have zero percent of the pie, it's possible to grow your business at a fast pace those first years.