Tech 'unicorn' IPOs are booming

Highly-valued tech startups are going public at a pace not seen in three years.
Four so-called "unicorns," or private companies valued at $1 billion or higher, completed initial public offerings in the second quarter. That was double what was seen in the first quarter, and equal to the number of unicorn IPOs for the entire year in both 2015 and 2016, according to data compiled by Goldman Sachs.These IPOs have seen mixed success. Here's a breakdown of the four former unicorns that made it to mark