Bitcoin is the most popular crypto currency as we know as its popularity and demands increasing with the time so it means that people can invest and earn bitcoin later and still will be okay to use bitcoin after some time.People are still allowed to invest bitcoin because there is no limit in bitcoin to the people to be the part of the bitcoin.Just keep it and hold it then you will notice its growth little by little.Most especially if you will hold it for a long time. So its nice to buy now then hold and sell later.