It is possible and it is happening right now. There is somehow some dump probably a successful ICO that is recently finished and now cashing out their collected Bitcoin. Or a whale that want to play with market and give FUD so that price will decrease more.
How? Does this whale have every currency in the world? The price is dropping everywhere. And the FUD needs to be in every language. How will they do that?
What you are suggesting is that someone is selling massive amounts of coins at a loss, spending a fortune on translators and trading surrogates at exchanges all over the world. And the payoff is a very slight chance of profits for a few hours at the most. Does not compute.
a whale is just someone with a larger amount of funds who acts faster/first because they expect a move in a certain direction.
it can be expectation of a drop because ETF was rejected, BU is threatening split, Mike Hearn says bitcoin is dead, or bitfinex gets hacked.
or it can be expectation of rise because ETF is being considered, halvening is happening, Japan said we adopt bitcoin,...
then this move starts the ripple effect, bots are alerted, the watchers start sending signals and the first wave join in and do the same and that move becomes bigger.
then the sheep come in. here you don't really need to translate that news (FUD or whatever) they will find it on their own and do the rest. they visit reddit, bitcointalk, or their favorite twitter bullshitter and find out what is going on and run scared to exchanges to jump in the river and follow the current.
this is incidentally the same time those "whales" are starting to do the exact opposite of what they did in the beginning.
this is my observation of what people call "whales manipulating" bitcoin.