Elon Musk is pressing major AI research groups and Chinese companies to test each other's models. He delivered that message while some in tech are asking for more caution around AI. Musk himself has major AI investments. Tesla stock slid after his remarks. Musk also was listed at the top of Forbes' yearly list of the wealthiest Americans. He again raised the idea of combining Tesla and SpaceX. Separately, reports say abusive material involving children remains on X, even though Musk committed to fixing it.