as before it is clear that the market cap is a result of the global Bitcoin activity or number of users and transactions. Speculation follows and emphasizes the trend.
for 2016 I expect two events:
(1.) the blocksize debate will solve itself under the pressure of rising tx numbers. That will create a lot of trust into Bitcoin and leads to increasing adoption
(2.) the blockhalving event will incentivize growing miner activity until 06/15. That automatically leads to higher prizes because it becomes obvious how limited the supply of Bitcoin is.