Not a bubble. The best thing for everyone would be for bitcoin to slow its growth and demonstrate its ability to retain value as users and investors adjust to its increased value. A stable bitcion allows for the rest of the alt coin market to grow, which in turn strengthens the market and ecosystem around bitcoin, making it more viable moving forward, and increasing its value in turn. Stable growth will cause less disruption in the alt coin markets. Sharp upticks and crashes will manipulate the alt coin market. But moral is, its not a bubble