Re: in spite of all this
I hope this link works
That should give you a year's prices on Bitstamp. Which I believe is now the top-dog exchange. Prices managed to crawl back above $500 this week, although it looks like they're on the way down again.
There's several interesting things to note. Firslty is the most obvious. Trading volume was steady, along with price, for 9 months last year. Then suddenly things went bonkers in December - and the price spiked up to over $1,000. Transaction volumes have been higher since, although at least some of that will be customers moving from Mt Gox (and others), as Bitstamp hasn't been top exchange for all that long.
Since the peak, prices have been much more volatile, but on a clear downward trend.
What we need is an understanding of the Bitcoin economy. Someone should be measuring its GDP. That might help explain what's going on. There looks to be a steady trade in the stuff, so I imagine there's various people selling stuff online. At least some of that is drugs and computer crime type stuff. But also legit stuff. Would be nice to know the mix? Silk Road has gone down since the price spike, and yet that doesn't seem to have dropped trading volumes. So either something's taken it's place, or it wasn't as important to the Bitcoin economy as people were suggesting.
The next question is 'what's changed'? Has there been a sustainable change in demand for BTC? As an example that CryptoLocker malware was demanding payment in BTC. It hit the big time around the December price spike. So was that the cause? Which would drop the price when it goes away.
One thing that does seem to have changed is the volatility. $100 swings in a day are not unusual. It looks to me like prices fall on large volumes of trading (as one would expect) - and several of those correlate with particular bad news days. Mt Gox's travails, and the 2 big days when China was said to be clamping down on Bitcoin.
There are also often big price jumps. Could just be natural, or people seeing the price lower than recently so aiming for a profit. After all, most people are presumably paid in real money, and converting to BTC to buy stuff. So why not buy a few days early when the price looks cheap? But given how stable the price and volume often are on other days, I suspect that we're looking at people 'investing'. People like the Winklevoss twins for example. Either seeing BTC as cheap, so investing. Or ones who've already got a holding, so are buying in whenever the price drops. In the hopes of maintaining the value of their previous investments. Looks like a losing game to me, but then it's not my money.
All guesswork of course. It would be a great project for some economist, or PHD student. EVE Online employ/consult a couple of economists, as they try to run their game economy with fewer and fewer inputs, and rely on interactions between the players.