Well, it's nice to have those kinds of idiots around because they help create a much higher floor for the share price should disaster strike (earthquake, fire, world recession, etc.).
Why do I call them idiots? Let's take the classic example of Microsoft. It was well recognized to have near-monopoly status in an exploding market of PC's for years before the DOJ slapped their wrist. From about 1988 all through the 1990's MSFT was considered so over-valued that value investors couldn't take a stake. I made a killing because I closed my eyes and bought the "over-priced" piece of sugar.
You need to look at a logarithmic chart to see the magic:
View attachment 496272
Yes, that's 10 cents a (split-adjusted)) share down there in 1996. It rose sharply to around 40 cents a share (split-adjusted) in 1998 (the plateau before 1990 on the chart). This is when people started saying it was "too over-priced". Remember, it was not actually selling for 10 cents or 40 cents a share, it was $30 or $80 depending upon where it was in the split schedule. People who didn't pull the trigger because it was "over-priced" missed out on becoming MSFT millionaires. As did most of the people who took money off the table as it doubled, then tripled, then became a ten-bagger and went on to be worth more than 1000 times as much.
Never hesitate to buy a great company because it's "over-priced". If it really is a great company it will be "over-priced" for years. But there is a reason people pay a premium for companies like this. Gorillas with room to grow. To my way of thinking, MSFT was never really "over-priced" (until near the end of the century), it was a screaming buy. That's how I see TSLA right now. Only a person who thinks small would call it "over-priced".
MSFT may be over-priced right now (but what do I know, I sold all mine the second time at $120-$130, purchased in the very low $30 range), whether it's over-priced now or not depends upon the size of the markets they are entering and their success in them. It might be a very good investment or they may be near the peak of thier growth. I'm not buying - I like TSLA a lot more.