China economic woes, I suspect, coupled with rising war fears.
The halfing had ZERO to do with the near-doubling of price late last year - that happened after the Chinese Markets announced they were able to take fiat payments (after a longish period they COULDN'T) allowing for a large rush of capitol into Bitcoin from Chinese investors.
It might be a factor in the current runup - but I suspect it's a minor one, as it would be more likely to cause a slower surge not the "spikes" we've BEEN seeing this past week.
Your right about China because the slowdown in China's economy has resulted in a capital flight from China's markets and the government has had to impose capital controls to stem currency outflows. In response, investors and Chinese citizens are using bitcoin to get around these controls.
But another one reason I've found is that bitcoin price will continue to rise since the growing realization that blockchain, Bitcoin's underlying technology, could revolutionize trading and money transfer mechanisms for major banks.
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