AI Landscape Shifts: Anthropic Valuation Reaches $183 Billion as Former OpenAI Leaders Launch New Ventures

The artificial intelligence sector is experiencing a significant reshaping following the tumultuous November 2023 leadership crisis at OpenAI, which has led to the departure of key figures and a dramatic increase in the valuation of rival companies. Melinda B. Chu, a prominent observer, recently tweeted, "> I think it’s actually sama’s and GDB and current Board’s duty of loyalty and care & fiduciary duty to OpenAI to sue everyone." Chu attributed these changes to a "failed 1-year plot and chaos" within OpenAI, highlighting the soaring valuation of competitor Anthropic and the formation of new AI companies by former OpenAI executives.

Anthropic, a leading AI research company and direct competitor to OpenAI, has seen its valuation surge to an estimated $183 billion following a $13 billion Series F funding round in September 2025. This significant investment, led by Iconiq Capital with participation from Fidelity and Lightspeed, positions Anthropic as the second most valuable generative AI startup globally, behind OpenAI. The company, known for its Claude chatbot, was founded by former OpenAI researchers who left due to disagreements over the company's direction and safety protocols.

Among the high-profile departures from OpenAI is Mira Murati, who served as the company's Chief Technology Officer. Murati officially left OpenAI in September 2024 to pursue independent ventures. In February 2025, she launched Thinking Machines Lab, an AI startup focused on building accessible and customizable AI systems. Her new company quickly gained traction, securing a $2 billion seed round by July 2025, which valued the firm at $12 billion.

Ilya Sutskever, a co-founder and former chief scientist of OpenAI, also departed in May 2024, following his central role in the November 2023 board dispute that briefly ousted CEO Sam Altman. Sutskever co-founded Safe Superintelligence Inc. (SSI Inc.) in June 2024, with a singular mission to develop safe superintelligence. SSI Inc. has attracted substantial investment, raising $1 billion in September 2024 and an additional $2 billion in March 2025, leading to a reported valuation of $32 billion.

These executive movements and the substantial funding rounds for rival firms underscore a dynamic and intensely competitive environment within the AI industry. The original tweet's assertion that "Employees left for these and other places" reflects a broader talent migration, as researchers and engineers seek new opportunities and align with companies whose missions resonate with their vision for the future of artificial intelligence. The organizational turbulence and shift towards a for-profit model at OpenAI following the 2023 crisis have been cited as contributing factors to these departures, further reshaping the landscape of AI development.