Another possiblity is that an institutionl (whale whatever) trader could be manipulating the market for a profit.
Have a look at the theory that USD Tether and Bitfinex are manipulating the market. It's not certain, but some decent reasoning about it is outlined
s/amp.reddit.com/r/Buttcoin/comments/7g05rk/bitfinex_admits_tether_has_no_usd_backing_there/]here, and it's possible that they would have more power over the market than it appears on the surface.
PLUS another say 50x that on the margin side just on the way up. Then ANOTHER 50x that on the way down margin trading.
There's a lot of discussion about the possibility of Bitcoin futures trading from major groups. If it happens, that could certainly open the gates for some pretty crazy manipulation.
Currently, it's also quite hard to get very significant margin on BTC (understandably).
If I was them, that is what I would do. Push large sums in and out just to determine how fast and how much money is actually flowing in.
Don't you think the existing statistics on volume (like on coinmarketcap) would be enough for them to analyse the market before orchestrating something like that?
That post on tether is interesting! It sounds like we are at the mercy of the guys that are behind it. Hope they are honest.
Bitcoin futures can already be traded on at least a dozen site. Bitmex.com probably the best and largest $3,000,000,000 traded in the last 24 hours making it the larget btc exchange in existence. $1m btc with 50x margin = $50m to trade . If the market moves 10% that would be a $5m profit. So the above example means theoretically somebody with enough cash to move the market up 10% and then back down 10% can make a huge profit $5m x two. And you can trade up to 100x leverage on Bitmex.
I think if you push enough volume in and out, you can determine how many $$$ moves the market what % . Armed with that info you could lots of things depending on who you are and what you want to do.