Do not try to find the whales. It is impossible. They are completely unknown with the help of bitcoin decentralization and anonymity.
Only some exchanges might have their identity and it's impossible to access them.
yes, we can only see proof of their transactions, a few days ago, I saw a transaction of 5700 BTC in an exchange, it seems that it was in a big market, like binance, Bittrex, Ethfinex and others.