When it comes to bitcoin, I'd say 1 bitcoin is equal to one ounce of gold. We just haven't reached that point just yet.
By magic?
The question is, is the growth of the price of bitcoin fuelled by speculators?
Answer that as "no" and you probably feel quite safe buying bit coins for speculation. Answer that as "yes" or "I don't know" and you should be weary of buying bit coins for speculation.