The team behind market manipulation is our own. Because we are the main actors who trade and investment which clearly are things that greatly affect the ups and downs of the market. I think we as users also have to be wise to do business in the crypto world in a good and not dirty way.
No, the number of people who are able to manipulate the prices is very few. Most of the people have a few number of coins compared to the whales.
You are right that we can affect the market. But that happens if many of the holders buy or sell simultaneously.