This all makes sense under QE and other easy money programs (which have a general tendency of inflating P/E multiples) but what happens if/when the programs stop? If 1999-2000 is any indication, those companies could easily see a 90% haircut and still be overvalued under traditional analyses (AMZN P/E is currently 1286.56, for example)
Well the stronger companies will survive and thrive, with their competitors destroyed. Amazon benefited from that survival effect coming out of the dotcom bubble and crash.
These Fed driven asset bubble waves are a huge wealth give-away to the biggest companies. They tend to be able to ride out the ups and downs, while their smaller competitors who get caught up in it as well, do not tend to survive the extreme down-turn (take Sun Microsystems for example: they modified their business to ride the exaggerated dotcom boom, their stock was worth $200+ billion at the peak, and their sales grew massively, and then it all imploded and nearly destroy Sun on the way down, and some would argue it did in fact; meanwhile Microsoft rode it all out just fine).
Lesson being, some companies get caught up in the exuberance, and they roughly speaking get destroyed, while their competitors thrive in the post-bubble period when the stock market & private markets aren't willing to fund competition any longer.
