I was joking around with a co-worker.  "Can I count the forex swings in my profit calculations?" If you're comparing S.DICE to any investment, for example an S&P 500 mutual fund, sure it's fair to throw it in.  But if you're comparing it to other bitcoin stocks or investment opportunities, they take the same swings in value.  So talking about whether S.DICE is a good investment with the assumption that you're investing bitcoins in another bitcoin denominated investment, I don't think it makes sense to talk USD.