There were at least two previous Bitcoin manias and bubbles. I remember a lot of hype when it hit $70 (from single-digit prices), and then again when it hit $1000. Both times people said it was a bubble, and then the bubble popped.
This is actually bubble #4. Here's an analysis of the previous 3: https://steemit.com/bitcoin/@huku/bitcoin-bubbles-a-brief-hi...