I mean i really find it hard to believe that one person could actually hold that much amount of bitcoin, since the blockchain network is technically anonymous there is no way to find out whether this wallet belongs to one person or an exchange website for example, and they say that the BTC came from tow different exchanges, means probably they are using tow address and this one as a backup, because there is no way that one person could get that amount just from exchange.
Why should that be so hard to believe ?
There are lots of rich business men who believed so much in bitcoin right from the onset and invested a lot in it.If you have invested $10k back then when it all started, we know that is like a chicken change to someone who was wealthy right from the beginning.
Moreover, there are so many whales and there are so many wallet with huge number of bitcoins than that which are not even exchanges, so all these ones about someone mysterious or someone being a Chinese and having a lot in his wallet is just absurd.