It is not a conspiracy theory, it is a reality, well, sort of, though I agree that the whales are not likely to be manipulating the price in the way most people think. They are just selling huge amounts of bitcoins - like it happened with the Mt. Gox coins, or buying likely as many coins occasionally. Obviously, such deals would lead to severe price swings which could be construed as price manipulation but I don't think it is. They are just doing what we all do, though the impact of their actions is felt by everyone in the market of course.