Bitcoin will never be a bubble. Tulips weren't a bubble. Their value was in a bubble. Bitcoins value tends to bubble up and simmer down, but that doesn't make the whole thing a bubble. Bitcoin is infinite and will rise like a stair way to heaven even gov't cant stop it. the only way to stop it is to find out who is the creator and yet.
Due to huge dump in the price many people say that bitcoin is a bubble and investing in it is just a waste of time and money. There is no future for bitcoin and soon it will disappear from the market. But I am very optimistic about the future of bitcoin and I am sure it will take over the market in the future. Other currencies will disappear from the market.