As an investment for the middle class, crypto-currencies are an ideal way. You can adjust the amount of investment, display profit when you want. The only thing in this you need to understand. Just investing and waiting is a very risky option.
Yes investing in bitcoin is a very good thing for all people in the world but you need to know and learn thoroughly about bitcoin and it's tricks if do this all things properly there is good and easy way to earn for a long time with good profit .