Lilium shares plunged 61% following the news. Shares of Lilium tanked Thursday after the air taxi firm said in a filing that its two main subsidiaries will file for insolvency in the coming days.

‘Our vision is to bring the world a form of travel that has never existed before,’ says Patrick Nathen, co-founder and vice president of product at Lilium. ‘Before we even put pen to paper, we knew ...