In my opinion, this is speculating, not investing. Nobody can predict what will happen to these two currencies over a 2.5 year period. Plenty of people can and will offer informed opinions about what may happen to them, but there are so many macro-economic factors that are utterly unpredictable that at best such opinions are guesses, albeit informed guesses.
So basically it's a bet, with the attraction that you will at least get your money back, assuming the provider remains solvent.