Bitcoin trading volume: what's going on? Since January, bitcoin trading volume on exchanges has been slowly dropping (more or less, on average), but it's had a significant drop around May 13th, and has stayed low since then. I checked the volume from BTC China mainly, but it seems several (if not all) exchanges exhibit this phenomenon. Up to this point, I'm just stating facts.

My question is: does anybody know about any reasonable explanation for this? I mean, based on facts, evidence, or meaningful experience on the subject. For example, has this happened before? If so, it could be some temporary/cyclic phenomenon, maybe (?). Also, if this happens to be some sort of pattern that has occurred before, can we expect the volume to go up again anytime soon? Is it some sort of "bad sign" ? (as in "this pattern is often followed by a big crash" or something like that).

I know nobody has the crystal ball, and I'm not asking for unfounded opinions; I just thought that maybe someone with more financial experience or knowledge on the subject (than me, which shouldn't be very hard) could shed some light on this.
This question could be asked of any financial instrument. Volumes decreasing is not a bad or good sign. It's simply something that occurs when volatility decreases. The market theory behind it might go like this.. Price has fallen to such low points sellers are no longer interested in selling. Buyers are still hoping for lower prices. This effect causes the price to trade within a range where anytime the price rises to an acceptably high level sellers begin to sell again and any time it reaches an acceptably low level buyers begin to buy. As traders notice the price is range bound more traders stop trading. This compounds decreasing volumes and also decreases the trading range. Eventually this will lead to reduced trading interest which can then lead to the price breaking out of the range in the direction of least resistance (as traders give up their respective buying or selling).

Sorry there is no provable answer to your question, as this is all market theory. However, if you were to look at different financial instruments historical volumes you would see many instances similar to what is currently happening in bitcoin's market volumes. This is a common pattern in markets and is normally described as not predictive of future events (range trading is often thought as having a random breakout direction).

https://en.wikipedia.org/wiki/Triangle_%28chart_pattern%29#The_symmetrical_triangle