It depends on fiat currency especially the Dollar for it's valuation.
Tell me. What are USD(or any fiat currencies) do when we got a major rise of btc valuation at october last year? Or at least what news/events that significantly related to the major rise?
I disagree with it. Btc valuation has nothing to do with fiat. Simply because the key factor of valuating BTC is supply and demand chain. Nothing fundamental aspect has do significantly into btc valuation