424B3

AST SpaceMobile changed its independent auditor from Marcum LLP to KPMG LLP effective July 6, 2021, with no disagreements or reportable events cited during Marcum's engagement. The company filed this prospectus supplement on July 9, 2021 to update information related to the sale of 28.75 million shares of Class A common stock and 6.1 million private placement warrants, along with up to 17.6 million shares underlying warrant exercises. As of July 8, 2021, the company's Class A shares traded on Nasdaq at $12.46 per share while public warrants traded at $5.20.