“Build in public”, the mantra of a new genre of Silicon Valley start-ups, is spreading fast. This novel approach to radical transparency for growing start-ups means that everything from hiring choices, executive compensation to even strategy decisions are blogged, tweeted, and discussed publicly. And while some start-ups make the choice to publicly disclose their journey, others are choosing to go down the most public route of all: Hitting the public markets. On July 1 this year, Astra rang the bell of the Nasdaq exchange and went public (via a Spac). On July 2, it was trading at roughly $15 a…