None of the big exchanges have had particularly big volume recently, so it must be fairly easy to manipulate the price. There have been long periods when 200 Bitcoins could affect things one way or the other. Three thousand Bitcoins today can have the same effect that required fifteen thousand Bitcoins last January.
That is what I meant in my previous post. At first sight, the volume
in USD is not much lower than it was a year ago:
Exchange ! 2014-05 ! 2015-05
----------+---------+--------
Huobi | 5.3 | 5.3
OKCoin.cn | 9.6 | 10.7
BTC-China | 1.2 | 12.6
Bitstamp | 1.9 | 0.9
Bitfinex | 1.7 | 2.5
BTC-e | 0.9 | 0.9
All values are very rough eyeball readings from charts, converted to millions of USD per day. Although Bitstamp lost half of its volume, Bitfinex doubled and the other exchanges varied surprisingly little. (BTC-China was practically dead last May, probably because of bank access problems and/or unattractive fee structure. But its volume today is comparable to that of October, when it had been revived.)
However, the price moves seem "different" than a year ago; more "bimodal": scattered large changes separated by periods of nearly constant price. Moreover, there seems to be much less rebound after those big changes: the price just stays where the big change dropped it off.
Could it be that most of the volume is now robots intensively trading fractions of BTC, with no intiative in moving the price; and the big changes are a few humans making their moves?
EDIT: lower --> not not much lower
(like how that Bob the builder site did for Gox.)
