Tech bubbles - When valuation is hard and euphoria is high

Bubbles are often associated with new technology. First, the new technology is hard to value since there is little past information. Second, there can be euphoria associated with the new technology. Expectations exceed reality. This does not mean the technology will be a failure. It just may take longer to be adopted than expected or the actual usage case will be less than extrapolated. Finally, when there is a tech bubble, not all firms will be winners. In fact, there may be high failure rates and even the best companies may not meet expectations. The economy may be better off even after the bubble bursts; however, there can be wealth destruction for those who invested in these firms. 

As a side note, we can add the nifty 50 from the 60's and early 70's and the tech firms of the 1920's which included radio, refrigeration, and autos. We have also had oil booms which were driven by discovery and technology. Of course, there have been housing bubbles which have ended poorly.