All the answers comparing bitcoin as an "investment" to stocks are missing the point..

You invest in bitcoin because its much more than an investment. You invest your time and your brain-skills to get to know about it and all the other good/ bad things it has spawned. It has reached a 0.5T USD market cap. The developments behind it are going to someday revolutionize the way we trade and the way wealth distribution happens.
Hopefully, It will make trickle down economics more than a trickle..