OpenAI's Biggest Investor Is Now Listed as a Rival — and One of Its Main Competitors Antitrust regulators have started looking into the Microsoft-OpenAI partnership, and a new detail was slipped into Microsoft’s annual report this week. Previous Article Mark Cuban Slams Kevin O'Leary on Social Media After TV Appearance: 'Take This Interview Out Behind the Barn' Next Article From Zero to Hero — How to Build an SEO Strategy From Scratch