The report added that the amount of Bitcoin held by whales was on the decline for the past five years, dropping over 22% from 6.7 million to 5.2 million, but more whales have entered the market this year and therefore it has started to increase.
there has never been any method to count how many whales there are and how much bitcoin they own ever. and this has not changed over the past decade. that is just how bitcoin works, all those who keep trying to measure whales size and count, like this article, prove how little they understand bitcoin!
bitcoin is not like a bank account where you could call the [centralized] bank and ask them how much money each "account" (that represents an individual) has. there are chain analyzers that are doing a pretty poor job trying to come up with estimates.
on top of that a whale who owns millions of dollars worth of bitcoin cares about their privacy a lot more than a regular users who has 20 bucks worth of bitcoin which makes all the estimations even less reliable.
I believe this "could be" a more reliable indicator. The total amount of dormant coins since 2017, https://bitinfocharts.com/top-100-dormant_3y-bitcoin-addresses.html
The strong hands are replacing the weak.