I don't think there is any one factory based on which bitcoin prices are moving. There are so many technical factors involved. An expert will be in a better place to tell you in details.

But apart from the technical aspect, any market moves based on two factors:
1. Demand - supply chain
2. Sentiment

The demand supply chain says, that the prices will be higher, if the demand increases/remains strong and supply falls and vise versa.

Secondly, being the pioneer of crypto currency, people are emotionally attached with this currency. There are many people who has stopped solo mining bitcoin a long time ago and currently mining other currencies, but they are holding onto their accumulated bitcoin with high hopes. That's the second external force that moves bitcoin market and prices.