OpenAI CEO Sam Altman, pictured, speaks with SoftBank Group CEO Masayoshi Son at an event in Tokyo on Feb. 3, 2025.Tomohiro Ohsumi | Getty Images News | Getty ImagesOpenAI has confidentially filed for an IPO with the Securities and Exchange Commission, joining the party a week after Anthropic did the same and days before Elon Musk's SpaceX is set to hit the public market. The artificial intelligence company, which is valued at more than $850 billion, has been gearing up to go public as soon as t...