Comment by donavanm

Yes. Simplistically, its all about incentives, “you've got to dance while the music is playing.” If a professional money manager doesnt follow the mania theyre going to significantly underperform their competitors/benchmarks. If they underperform for multiple quarters theyre going to lose allocation, customers, and their jobs. See also the “perma bears” who have predicted “15 of the last 3 recessions.”

As an individual you can change your risk profile by rebalancing or profit taking during the mania. trying to find quality places to put your gains to reduce the downside risk. That said, in even a moderate correction youre going to underperform the index due to the silly magnitude of those mania gains over time. Eg an additional 2 years of +30% and then a 25% correction is going to outperform your “safe” 7% returns.