There is something that the chart does not show. Bubbles are most well known in the stock market. The chart shows a classic stock bubble, but is that comparable?
With a stock the money from investors is needed to operate the company offering the stock. When the value reaches a critical low and the company becomes insolvent, it all goes to hell. Bitcoin is different. It does not need the money to operate and the price can fall or rise without destroying it's utility. No matter how low it goes, it could go up again. Not true of stocks, bonds, derivatives and most other financial instruments. The closest asset in terms of behavior may be gold. Gold has seen countless bubbles in the last 4000 years, and is still able to set new highs.