In my observation in bitcoin price !!
I think the WHALES are the manipulators of shifting price of bitcoin and alt coins
Why?
Because whales are buying huge amount of coin, in this case there will be a sharp rise in prices and also because of this demand will increase and many investors will be able to invest, so the outcome is,WHALES had a large profit on their money or capital, i think this is why the alternative currency increases.
and after they buy it they will sell their coins that will cause a sudden fall in its price of alt coins.
You have a point there mate. Whales will be whales, they can manipulate the price on their favor. That's why we casuals should be cautious specially in altcoins because we don't know when those whales are going to dump to take home the profits.
As for bitcoin, they can still manipulate but for me its much harder as compare to altcoin. There are so many whales in bitcoin that most of the time it will be just a few whales who dumps the coins simultaneously or put a coordinated effort to bring the market to its knees so that they can buy it cheap later.