Whales can't pump it to 20,000 alone, they'll start the ball rolling and then let the small fish push the price up. They'll also offer support whenever theres some downward pressure on the price. But 20k won't happen overnight.
Yups thats very exaggerated on our part that would expect some individuals can push the price to $20,000 overnight even two whales im sure dont have the power or capacity to make it real,because were talking atleast hundreds of billion dollars just to make this great coins enough to consider in &15,000 price,when bitcoin reaches $20,000 last 2017 in December the market capitalization is almost 800$billion and i dont think sole capitalist has this hugeamount