Can venture capitalists tell these billion-dollar 'unicorns' from jackasses?

CB Insights has compiled this list of private companies now valued at $1 billion or more by their investors. Tops include smartphone-based driver service Uber, overnight-flop service Airbnb, smartphone-maker Xiaomi, spy data analyst Palantir; plus a lot more smartphone-focused services (Snapchat, Square) along with mysterious medical-testing service Theranos and some other speculative and pre-profit companies. 

There are now so many of these "unicorn" valuations, counting on small firms making big future profits, that venture capitalists joke most will turn out to be "horses," says Matt Topley of Fortis Partners, who sent me the link. Or maybe "jackasses," if the bubble bursts before firms can cash out. 

Sad to say there isn't a lot of Philadelphia-based capital or management on the list. Josh Kopelman's and Chris Fralic's First Round Capital is in Square, Blue Apron and Warby Parker; Wellington Management (of Boston and Radnor; clients include Vanguard Group) is in WeWork, Moderna and four others.

West Conshy-based Michael Rubin's Fanatics (online pro and college team gear sales) makes the list; so does Bloom Energy, whose Delaware-ratepayer-subsized "Bloombox" plant in Newark has so far failed to produce promised jobs or sales despite costing electricity users down there millions of dollars a month. Will they get to market?