AST SpaceMobile Inc (NASDAQ:ASTS) shares are set to plunge more than 22% a day after it raised US$206.5 million from investors including Google, AT&T and Vodafone as the space-based broadband group announced a US$100 million public share offer. The public offering is priced at US$3.10 per share, a sizeable discount to the US$4.16 at which the stock closed trading on Thursday.  Vodafone was an existing investor in the company, with AT&T and Google joining as new investors to raise a combined US$155 million, ...