I think you need to trust Einhorn on this one. The author Alex Willhelm sounds like quite the apologist for the tech and venture industries. I'm not going to get into the technical details of the valuations because Einhorn does a much better job of that(pdf to Greenlight letter <a href="https://www.streetaccount.com/FileLinkHandler.axd?filename=STORYID1475487_Greenlight%20Capital%201Q14%20letter.pdf&e=0&u=73988" rel="nofollow">https://www.streetaccount.com/FileLinkHandler.axd?filename=S...</a> ).<p>I argue though that there is something more at play here than just a bubble mentality around tech stocks. Low interest rates have caused investors to seek higher returns in riskier ventures. In my opinion this could be the cause of why so much money has gone into the venture capital industry. So along with the bubble popping because there is no greater fool to buy also consider that as The Federal Reserve begins to curtail its easy money policies all riskier assets are likely to pull back.