Also investors would not just be using bitcoin for growth, but as a store of value. Yes there is hot money going into bitcoin in the heavy growth phase, and when growth is not so quick that money will leave for better opportunities.

However, in the meantime a number of investment opportunities that are only denominated in bitcoin should become available allowing those investors looking for growth to stay within the bitcoin ecosystem. So as long as the bitcoin economy evolves and develops (things like profit making companies etc.) it will continue to grow , and is not likely to be a bubble.