Looking at the 2-year graph, the price is still above what it was for most of 2013, before that massive spike in November 2013. I wonder if what we're seeing is Gartner's Hype Cycle. The drop isn't as rapid, but it seems conceivable people who lose interest still wait some time to sell their bitcoins.
If we are, we haven't hit the bottom of the trough yet. It's now at $233. What is interesting, is that these drops are making mining unprofitable, which will likely make some operations shut down. Also, we might find out which exchanges are running a fractional reserve.
So, I've read some things since, and I think I might have been wrong. Some people think the November spike was largely due to BTC China, and Chinese interest. Since the spike, the Chinese government has steadily increased regulations, with perpetual rumours of an outright ban. It's possible it's still Gartner's cycle, with China as a major player. But it's also possible the steady increase in regulations has steadily scared Chinese adopters away.