You are not alone in wondering what will happen, the price of BTC is climbing at unprecedented rates, the last few days alone has seen incredible rises, I am literally watching the balance in my SR account grow by the minute. Right now I can only speculate that demand is driving the increase and a lot of people are holding onto their coins as the price sky rockets. For the 'bubble' to burst if indeed it is a bubble there would need to be some sort of significant event to precipitate a crash e.g. a major successful hack of coins thus causing panic and the flooding of the market as buyers sell off their coins. Markets globally are often influenced just by perception as people speculate on what they think 'might' happen, right now the only direction seems to be up though and I can't see it slowing down anytime soon to be honest as more people clue into the potential gains to be had and hoard coins, something I admit I am now doing myself. This is of course just my opinion and I don't have any real facts to back any of that up so anyone with a competing view feel free to shoot me down in flames