No. It is not too late because there are many people who uses bitcoin who wanted also to invest but they have a question in their mind if it's too late. It's not yet too late because as long as bitcoin never stops, investment will never stop also. As long as there are users, there is bitcoin and if there's bitcoin, there will be an investment.
Its never too late to invest in bitcoin and the price of bitcoin will never become a bubble. As of now the number of people who invest in bitcoin becomes double and I think in the near future many people would invest in bitcoin and tell to them that do not scared because bitcoin would never become a bubble.