"Bubbles happen when everyone in the market is stupid. No. Bubbles happen when interest rates are low or via other mechanisms ( QE, etc ) excess capital is cre

"Bubbles happen when everyone in the market is stupid. No. Bubbles happen when interest rates are low or via other mechanisms ( QE, etc ) excess capital is created." --- Nobody has or can define a bubble. Nobody can see 30+ years into the future. Right now, 30 year treasury bonds are paying about 2.3%. If the capital markets are efficient, then there is no free lunch, so you can expect returns of stocks in the next 30 years to be essentially the same or about zero if inflation stays low and all nominal income will be from dividends. Is that a bubble in stocks or bonds? Well, I think what will determine if people call it a bubble in hindsight is if inflation goes up and interest rates as well. But that is not expected by most.