As to the USD price, I am less sure. My weak working hypothesis is that it is driven by adoption + projected future adoption. That is, how much people value it means how much they value being in on this particular ledger.
(Why are those things almost certain? Consider the scale at which Bitcoin operates; then take a look at ACH, Swift, Visa, Mastercard, etc. We are talking about orders of magnitude in difference. For all its gains over the past few years Bitcoin remains a tiny niche.)
In other words, don't view Bitcoin as money; view it as a system for transferring money and converting between different countries' money.