I think, Bitcoin is undervalued because it can provide a way out for unstable currencies (Venezuela, some African and Asian countries, maybe soon western countries) or to avoid regulations (China, Russia) and of course, for unlawful business (money laundry, blackhats, drugs). That's probably the real value drivers at the moment.
The biggest risk is regulation. Exchanges have to operate somewhere. But I guess, its hard to regulate something that is global (looking at you tax heavens).