May 1, 2014 By Chris O'Brien, McClatchy News Service
Venture capital rising to levels not seen since 2001. Companies with no profits going public. Billions of dollars being paid for start-ups.
These and other signs that the tech boom may be taking an irrational turn are leading some notable investors to utter the dreaded word "bubble,"waking up the ghosts of an era many in Silicon Valley would prefer to keep buried.
Has Silicon Valley once again lost its collective mind?
Hedge fund manager David Einhorn thinks so. "There is a clear consensus that we are witnessing our second tech bubble in 15 years," he warned in a note to his clients last week. "What is uncertain is how much further the bubble can expand, and what might pop it."