With less than a month to go, I find Brunic's suggestion of a gradual rise in the exchange rate to be most likely.
Why? Demand is currently about USD$550,000 per week, or approximately $78,500 per day - that's just to keep the price relatively even, based exclusively on Gox numbers (~80% of open exchange markets). If that level of demand remains after the Great Halving (had to say it), then price will be rapidly bid up. However, there are other factors involved which we'll list, with a minus (-) denoting negative price pressure and a plus (+) for positive or upward pressure:
- + Great Halving
- + Demand remains stable
- - Additional coins may be sold from existing stock
- - ASIC devices are delivered
- + GPU mining force reduction
- + CPU/GPU botnet processing share decrease
We could assign weighted values to each item depending on subjective assessment of impact, but without knowing how quickly the GPU->ASIC transition will be, or how many coins from existing stock will be sold at market, we're grasping at straws.
Although unreliable and unscientific, there does seem to be a near-insatiable demand for bitcoins through off-exchange OTC channels. Where this demand is coming from, and whether it will spill over to affect the more official pricing is not within a reasonable range of estimation.
Assuming that the only variables which experience major shifts are the Great Halving and the introduction of ASICs, I think it's very reasonable to expect a sustained rise to and through the $12.60 level toward the low $20s. It's hard to see demand significantly decreasing at this point, and if it rises by ~30% from present the 2011 high comes into view - sustainably.
If additional stock is liquidated, the pace of price rise will be slowed somewhat. That's all, though. Whether it takes weeks or months, the price will
rise against flowing stock. Aside from that, the most influential wildcard remains the ASIC situation - making it cheaper to generate bitcoins will draw competition. The difficulty may go 100x higher than it is now, maybe further. During that ASIC proliferation period, there will be downward pressure on prices as miners seek to recoup their hardware investment - with the ability to generate more efficiently, they can offer at lower rates than with FPGA or GPU systems.
The entire Bitcoin system is still vulnerable to failure at this point, and one thing is certain - volatility will rear its head. Keep in mind that the size of the Bitcoin economy is now much greater than it was in the 2011 bubble, so swings in a $10 range won't be as enormous as they would've been then. They will be immensely profitable moves.