One of the best known today is the Grayscale Bitcoin Trust fund. The fund currently holds around 330,000 BTC, which is 1.7 percent of all BTC in circulation. Satoshi Nakamoto is thought to have an apparent ownership of 1 million Bitcoins, and some of the users who bought bitcoins when bitcoin was first launched could also be among these whales. so yes, of course there are whales, but these accounts could also belong to a centralized system that holds people's bitcoins.
Grayscale is not an individual but rather institutional investors that holds and manage all the assets invested to them by their customer. I agree that the only known individual that possessed huge amount of Bitcoin and true whale is Satoshi but theres a lot of Bitcoin whale investors investors that privately stored there coins in there wallet like Elon Musk, Cz and other big person in crypto that too obvious that has the capacity to own huge chunk of Bitcoin without the need to prove by themselves.
My questions
~Are there private individuals who own and posses such amount of Bitcoin?
~Why will one posses such amount as an Individual?
~Are there any consequences to this?
1.) Yes they are but as the word private itself is self explanatory that we will have a hard time to track them 1 by 1.
2.)Why not if he/she truly believes on Bitcoin?
3.) What kind of consequences you are pertaining? Because only the price volatility is the only downside of Bitcoin which will be negligible in the long run if you just hodl.