I traded precious metal futures and stocks for a long time.
Even the holders of some pansy ass mid-cap stock scream manipulation when the price doesn't go into their direction.
While there for sure is "manipulation" (btw. what's the definition for manipulation?? Every buy & sell, bid & ask is manipulating the price.) happening in the financial markets I know for certain that charts never lie.
When you do not have much money you can only trade passively, need to observe what the chart does, where the important levels, inflection points & divergences etc. occur and then act accordingly. This is because you are low in the food chain.
The opposite is true if you are the apex predator and have loads of cash. Then you are always! "manipulating" the market, simply because you are so big. At your buy & sell levels the price tanks or rises, you create and shape the significant levels in the order book and others need to observe this behaviour or get slaughtered.
I'am sure that the investment funds that are getting involved in crypto currencies might have incentive to try lowering the prices by fat block orders, or it might just be the case that some random people want to sell large quantities of Bitcoin and create sell pressure, but whatever it is that makes the price drop, when I observe this kind of stuff in a weak market I try to get out of the way. (Of course this is always easier said than done
)