the dutch tulip bubble (1630, first ever recorded)
the south sea bubble (1720)
Japan stock/real estate bubble (1990)
.COM bubble (2002)
USA housing bubble (2008)
Where is the next bubble going to appear. I know the bond market is in a 100 plus bubble and this is where im placing my bets.
You forgot the crypto bubble of 2017.
It's hard to make a case for it not being a bubble with that massive 70% drop persisting for months now. Essentially, bubbles don't reveal themselves until after they pop. You may suspect a price is unsustainable, but if people could reliably predict where bubbles were going to form or what was already a bubble, they would be able to avoid them. By nature, you don't know something is a bubble until after it bursts. The fact that something crashes and has great difficulty recovering helps to inform whether it was a bubble. Exactly like Bitcoin in 2018.