I don't think it's a bubble. The advancement of cryptocurrency being used and accepted by a lot of merchants online has an increasing growth! That is why it is high time to invest. A lot of cryptocurrency are now emerging and the originals are bitcoin. And it is never too late to invest. One of the best is Ethereum! I like that www.propthereum.io and their whitepaper is accesible for everyone. It helps me understand the whole concept. Please check it out.