Bitcoin price spiked by $300 in less than a minute when Bitcoin spot futures exchange Bitmex went down. This is basically proof that the futures market is bad for Bitcoin as a whole(we already guessed this because Bitcoin price has been on a downward spiral ever since the futures markets opened up in mid December of last year), and most of the contracts on the exchanges are short-sell contracts. The recent price moves is very convincing that many of the sudden drops and sudden rises that happen within a few minutes are coordinated short positions and perhaps long positions. Unlike CBOE and CME, Bitmex offers spot futures which means you can hold them for any amount of time you want, making it easier to coordinate short-sells and long positions. Back a few months ago, when a large short position got liquidated, the price of Bitcoin jumped $1000 within a few minutes and now price jumps $300 within 1 minute when a futures exchanges goes down. This is pretty solid proof that the contracts on these exchanges are being used to keep the price of Bitcoin down these last several months and the way that contracts are settled needs to be looked at a be in the discussion for regulation and oversight.