i think best time to invest.... NOW. because tomorrow price will increase. this motto is able for all days. TTM.
It's just a prediction and also bitcoin will not always increase sometime bitcoin will fall so we have to choose the right time but to invest bitcoin is very not recommended for now because the current price is very high
i am talking from previous few weeks when the price of bitcoin was trading below 1270 USD that in recent time the price of bitcoin is expected to increase more and more and very soon the price of bitcoin will start increasing and now we can see that the price of bitcoin is trading above 1300 USD level that is really a very heavy price.