... The point is indeed who or what is trying to prevent the price from going up.
Just like Soylent Green, it's people.
They keep selling and selling which makes me wonder, when will these guys run out of coins that they are constantly selling. They have been controlling the price for quite a long time now.
No, "they" don't "keep selling and selling." They buy when the price is low & sell when the price is high. That way, they never run out of coin. It's called trading.