It could be an indicator that a lot of people invest without regard for foundational questions like "does this valuation make sense" or "does my ownership interest grant me any control of the company?"

And I'll be the first to raise my hand on that front. On the face of it, I'm not really interested in owning a stock like this. But I've stopped picking stocks entirely, now I just invest in the stock market through index funds. And there are a lot of people like me -- enough that Vanguard funds own about 5% of just about every public company you can name. People like me are essentially saying, "We don't really care what this company does, how much it costs, or whether its stock can vote, we want to own 5% of it." (And that's just Vanguard -- there are plenty of other passive funds out there, too.)

In an IPO that sells 10 or 15% of the company, these "buy at any price" investors can eat up a pretty big chunk of the available shares. So all it takes is a few investors to say, "yes, we want to buy at this valuation," and the rest of us will blindly follow.