Likely the evidence for a bubble that would be risky for our economy is the surprisingly large number of recent unicorns, that is, private companies who have a

Likely the evidence for a bubble that would be risky for our economy is the surprisingly large number of recent unicorns, that is, private companies who have a recent funding with a post money evaluation of $1 billion or more. One reason for so many unicorns, that is, such valuable private companies, is the reluctance of significant private companies to do an IPO. Reasons include (A) having to try to please Wall Street that has a very limited view of real progress for a company and a very short term focus and (B) the overhead of Sarbanes-Oxley. But I believe that you will find that a surprisingly large fraction of the unicorn fundings are more like traditional private equity instead of venture capital. So, for the unicorns, the high post money evaluation may be at high risk (bubble bursting), but, due to the deal terms, the last investor is relatively well protected and at only low risk. That high post money evaluation was just something out in the ozone anyway, a long way from that much in actual cash, so that, if such high evaluations suddenly disappeared, that is, the bubble burst, then the effect on the economy would be minimal. So, why do these goofy late stage fundings and unicorns even exist? The companies may want the cash from the equity funding and not want to attempt an IPO, and the private equity investors see maybe an upside, if the bubble doesn't burst first.