Can I say something about this phenomenon?

While the historical data helps us to understand accuracy and the risk associated with 2 period in question, it's unwise to challenge the summation for that is actually talking for the sake of talking.

So, what doeI want to say? I see this adage as a good opportunity to both rebalance and relook our existing portfolios. Good stocks can be rebalanced while those fails to meet expectations can be either reduced or removed to cut losses. It maybe alsoea good time to take profits either trimming our holdings or sell all if our analysis of that particular stocks has turned lesser as a growth stock and little dividend benefits.

I welcome any comments on this as mutual learning helps all of us. Good luck!