There`s no single manipulator,who is rich and powerfull enough to push the prices down.
There should be a group of big crypto whales and they sell together,forcing the price to go down.When the prices go down,all the small traders start to follow the trend,and eventually the market is manipulated.
Slow and steady decline means small panic.Fast and rapid price crash means big panic.Both scenarios can be created by manipulators.
What do you mean by "artificially bring the prices down to cause panic selling"?