term whale in bitcoin is most likely derived from gaming
https://venturebeat.com/2013/03/14/whales-and-why-social-gamers-are-just-gamers/
or gambling
https://en.wikipedia.org/wiki/High_roller
also on your point on buying during uptrend isn't proftiable in the long run you will lose money
as the old adage goes buy low sell high
so you want to enter markets during lull periods before action as happened and HODL until sell
also never take advice from trading trollboxs nearly all is FUD and manipulation tactics especially on poloniex and rep system is fake with heavy fudsters repping each other up early on so that being pink means nothing and mods do very little against.
Wow! Thanks for this! As a newcomer clearly I am still learning. I will make a few adjustments to the post now as not to give anyone bad advice...