How rational are whales?
When you have as much money as they do, you have to be careful to preserve it. I doubt that the biggest whales are doing all the thinking by themselves - I'm sure they have plenty of financial advice.
Are whales inevitable?
Yes. Under capitalism, inequality is inevitable, just as there is inequality in fiat currencies. However, the extremely dramatic increase in price over the last several years has resulted in some people having much more wealth than they would otherwise have had, so the distribution will probably even out
to some extent over a long time.
And how mature is the bitcoin market?
Not very. The volume is quite low compared to traditional investments and many people who are involved are amateur investors, which contributes to the price being so unstable. Whales have a huge amount of power over the price.