Prices are set at the margins so even a small number of additional bitcoin users can greatly increase the exchange rate when there is a limited supply. Is this a "bubble" or is this just the continuing maturation of the market itself?
Think about this: with around 21 million bitcoins maximum, if even just 5% of the world population wanted to use it (roughly the population of the US, say 300 million people), that would be around 0.07 bitcions per person if evenly distributed. The market is huge with the number of people in countries with currency issues, lack of freedom, lack of transparency - shoot, it might even be super-majority of the world population.
So, I do not know if this is a bubble, or growth. The only way to know for sure is to look back in a few years. ;-)
There are so many threads about this "bubble", I decided to make one BIG thread. Post your various findings and explanations here, and let's keep things organized instead of posting 1,000+ ALL CAPS posts saying "OMG BTC IS $140".