The Fuzzy Science of IPO Measurement

As the tech IPO bandwagon continues, journalists and investors are keeping score. The only problem is no one seems to have the same definition of success. 

Was Zoom a successful IPO because its share price shot up 72% on its opening day and now trades 161% above its IPO price? What about the fact that the company sold relatively little stock? Or take Slack, which tried the novel approach of a direct listing. Its opening days were smooth but the price has slipped. What should we make of that?