Tesla shares fell more than 6% after its all-electric Cybertruck failed a live demonstration of its "shatterproof" glass windows during launch. CEO Elon Musk's net-worth fell by $768 million in a single day to $23.6 billion, Forbes said. Chief designer Franz von Holzhausen had thrown a steel ball twice at the Cybertruck's armoured windows, which shattered the windows both times.