http://www.coindesk.com/kncminer-declares-bankruptcy-cites-upcoming-bitcoin-subsidy-halving/... so this is the real reason behind the rise, or rather the reason why bitcoin was being held down and now allowed to rise. KNC miner was going broke and the chinese miners got wind of it so conspired (probably in cahoots with some notorious shorts) to hold price below cost of production until KNC was bust. As soon as that happened they let the price go up to a new level ... where they think they can manage it.
These shennanigans have released some important information into the market, givn some of the game away so-to-speak. Cost of production is somewhere around $480 at current difficulty so after halving that will be around ~$960, by a simplistic 1st order estimate. Bitcoin price has never spent large amounts of time significantly below cost of production so it is a good bet that 3-6 months after halving bitcoin price is going to be ~$960.
BTC price doesn't depend on the production cost. Market sets the price at which one is willing to purchase BTC not miners at which they're willing to sell BTC. Market couldn't care less how much in electricity it took to produce 1BTC, simple supply and demand, where supply is fixed
the main sellers are miners, and to some extend also shops that accept bitcoin
sure there are some investors who sell and buy back cheaper, but since they buy back cheaper they end up buying more coins than they sell, so in effect they don't count as supply, but as demand. Unless they hold their profit in USD, in which case they'll become less significant every time bitcoin gains value, because their USD becomes worth less, so that makes them less powerful.
So if the production cost of bitcoin increases, we can expect the price to follow suit. t won't be an instant increase n price (some people think the halving will immediately drive the price up as soon as the first block is mined with a 12.5 BTC reward) of course this will not happen.
But a few months after the halving the new stable price will become much higher than the current price. And at least double of what it is now.