I know these illustrations are based on assumption, but for the price right now? I think 100 to 500 BTC can consider a whale since those value can noticeably affect the market and make a wave.
Im not sure if you get my point. Whales could be owner of even 1coin if that coin value is really huge. Thats how we define the whales capacity. I didnt share this as the main guide but simple thought that I searched in the internet as OP has no idea right. But Im not saying the price is based on curremt market and probably this illustration has been long made.
No one can fan out the description of whale in the crypto linguistic. Just a term made by people who have a lots of fund. Not even sure if this is on the dictionary and has been accepted by general.