Elon Musk’s move last week to combine SpaceX and xAI has created one of the world’s biggest and most valuable private companies, which analysts say offers a mix of potential growth and financial risk as it heads toward public markets. The two companies are very different. SpaceX was founded in 2002 and has established itself as the premier nongovernmental space exploration operation. Musk’s xAI venture was started less than three years ago to focus on AI and more recently social media. In