I think it is not about market manipulation anymore. It is about people's foolishness! One someone popular saif negative about Bitcoin, people will usually sell their coins without doing some research if the statement of that popular person is true. People tend to idolize other people who achieved something that they didn't.
Fair enough but they don't seem to buy i that much on the good news.. Coud it be bad news, followed by a major sell off to spark te downtrend? so many times there is a big dump for no reason.