how are you defining "market manipulation"?
How do you know its not a large seller taking profits from
a trade that started weeks ago in the $400s?
How do you know its many traders taking profits because
price has entered overbought territory?
How do you know its not miners unloading coins?
Market manipulation is a deliberate attempt to interfere with the free and fair operation of the market and create artificial, false or misleading appearances with respect to the price of, or market for, a security, commodity or currency. Market manipulation is prohibited in most countries, in particular, it is prohibited in the United States under Section 9(a)(2)[1] of the Securities Exchange Act of 1934, in Australia under Section 1041A of the Corporations Act 2001, and in Israel under Section 54(a) of the securities act of 1968. The Act defines market manipulation as transactions which create an artificial price or maintain an artificial price for a tradeable security.
Wikipedia definition - Are you saying this isn't happening?
It's not against the law when it comes to BTC as this market is unregulated...