Well, the answer is yes.
A slew of reputable investors have come out to say we are in a bubble. When I say reputable, we are not even talking about David Einhorn or Dan Loeb. Here's market veteran Jeremy Grantham who has studied bubbles over 50 years and he is telling us, we are in a bubble and this may become the biggest bubble we have seen.
https://www.gmo.com/asia/research-library/waiting-for-the-last-dance/
There are a few characteristics about bubbles. First it is when valuations are inexplicable. Look at Tesla.
We discussed this before. This company has never made money for shareholders. It produces less than 500,000 cars and yet it is now bigger than almost all of the global automakers combined. In a bubble, it is easy to just look at the stock price. Nothing else really matters. Dividends, accident and safety record, resale value. Well, who's tracking anyways. People who bought Tesla look like heroes....