Banks and whales are not comparable at all. Banks give loans, take deposits. Whales buy/sell asets on a large scale and use that to manipulate the market. One does it for their and public's benefit while the other only wants to profit from the market movements. Whales are also loan sharks but that number is limited and they are usually predatory in nature.
Besides banks have a lot more number of services to provide, whales are not intended for that.
Yes, the difference seems too big to be compared. Banks accept money on deposits in order to make money on issuing loans, but at the same time they give part of the profit to depositors, in addition, banks are entire structures with great functionality, and the whales are aimed only at making a profit from the transaction, while trying to manipulate the market if possible , or a separate coin.