https://techcrunch.com/2021/02/11/as-more-insurtech-offerings-loom-ceo-dan-preston-discusses-metromiles-spac-led-debut/

MetroMile began trading as a public company yesterday. Its exit from the private market was accelerated by its decision to combine with a special purpose acquisition company, or SPAC.

Such transactions have exploded in popularity in recent years, bridging the gap between a host of richly-valued private companies and endless bored capital. SPACs raise cash, go public and then merge with a private entity. The SPAC then dissolves itself into the combined entity, a process that often includes an additional slug of money (PIPE) for good measure.