"I'm sure that in 20 years there will either be very large transaction volume or no volume." -- Satoshi
he said it very true. he gave a straight away answer for all the questions. but we all are thinking that bitcoin will be at the top after 20 years because of current trends but nobody can say what will happen to bitcoin in 20 years because it is a very long time.
Well, that is probably right (the possibility is always there for both outcomes) but we do hope that it would be on the "very large transaction volume" side. Many things can happen for 20 years just like the past years, so nobody really knows/predict. What's important is, bitcoin continually grow as days/months/years passes by, we just have to go with the flow and hope for the better