To be fair, there often is always someone warning of a bubble. As the famous quote goes, economists have predicted 9 out of the last 5 recessions. The problem is picking out who to listen to. (On the other hand, I don’t have detailed knowledge about whether there are more warnings from more reputable sources than usual before actual bubbles).
The subprime mortgage crisis of 2007-2008 seems like an obvious example, as is every other bubble. Warnings get ignored because “this time it’s different”.
To be fair, there often is always someone warning of a bubble. As the famous quote goes, economists have predicted 9 out of the last 5 recessions. The problem is picking out who to listen to. (On the other hand, I don’t have detailed knowledge about whether there are more warnings from more reputable sources than usual before actual bubbles).