The trend of bitcoin exchange value could, in my opinion, be divided in three phases thru now.
The first, up until 32$, the second part from 32$ to 10$, then the current phase caused by the halving of the block reward.
The two forces driving bitcoin prices were and are the internal inflation of Bitcoin (compared with the other fiat currencies) and the adoption rate from actual users that hold bitcoin and must buy them at the exchanges or for goods and services.
The first force (inflation differential) was a negative force up until the halving of the block reward, because the internal inflation of bitcoin was (initially) a lot higher than the inflation of US$, €, Yen, yuan, even of the Argentinian Pesos. But is was a predictable always diminishing force. And after the halving of the reward it become a zero or positive force (the internal inflation of the bitcoin is smaller than the internal inflation of US$, €, Yen, Yuan, etc).
The second force was the adoption rate, that was explosive initially and continue to grow at leaps and bounds. This is something near alway positive , as the network just never shrinked in the past.
In the first part (0.001 to 32$) we had a lot of adoption, mainly for online gambling and selling some internet services. This was explosive and overcome brutally the negative forces of inflation.
When it hit its limits, the negative of inflations took over and moved the price lower.
At some point the diminishing negative force of inflation become to be equal to the grow of the network adoption and demand for bitcoin (when it hit the minimum of 2$).
Some savvy investors could have anticipated the intersection point and bough bitcoin before the actual minimum could have happened (this is the nature of speculation and speculator).
Then, for a "long" period, the two forces was nearly equally matched, when the BTC exchange rate risen from 2$ to 10$.
Then the nearing halving of the reward, the increase size of the network and demand for hold bitcoin kicked in. The halving caused a reduction of the inflation rate of half, making the differential with other currencies positive (even if the network stopped to grow, the increase of bitcoin would be smaller compared to the increase of M1 of other fiat currencies, so BTC should increase in value compared with fiat currencies).
Essentially, it is like the rivers and the creeks the salmons (purchasing power) go back to reproduce instead of staying on higher grounds moved back, so instead of swimming upstream the salmons found themselves swimming downstream. A lot easier. And a lot funnier for the bears (bitcoin holders) to catch a lot of them. The main problem would be in some places there would be more salmons than water to swim.
Essentially, in my opinion, the media line of the trend channel depicted in the OP could be passed like butter, in the right circumstances.
http://bitscanner.blogspot.co.uk/2013/11/btc-update-monday-18th-november.html (for the OP and the chart)