Well, supply will be cut in half, and unless you also believe that demand will be cut in half at the exact same time, price will rise. It's really that simple.
Nope, sorry, I can't see it that way. If it were so, the chart would show a step change in price at the point of halving. Demand is to a large extent already discounting (anticipating) future events, because it is so tied up with speculation. The flows and changes are complex. That's the reason you often see an opposite reaction ( to that expected) when an anticipated price sensitive event happens.
edit : Merry Christmas !!