Anthropic, PBC, an American artificial intelligence company headquartered in San Francisco, California, completed a $3.5 billion Series E funding round in 2025. The round was led by Lightspeed Venture Partners and valued the company at $61.5 billion, reflecting its rapid growth and prominence in the AI sector. This funding followed a period of significant product development and expansion for Anthropic, which is known for its Claude family of large language models.
The Series E round occurred amid a broader surge in AI investment, with competitors like OpenAI also raising substantial capital. Anthropic's valuation of $61.5 billion positioned it among the most valuable private AI companies globally, trailing only OpenAI. The funding was intended to support Anthropic's research into AI safety, expand its computing infrastructure, and scale its commercial offerings, including the Claude models and associated tools.
Background and Founding
Anthropic was founded in January 2021 by seven former employees of OpenAI, including siblings Daniela Amodei and Dario Amodei, who serve as president and CEO, respectively. The company's mission is to promote AI safety and ensure that advanced AI systems are developed in a responsible manner. In May 2021, Anthropic raised $124 million in its initial funding round, which included investments from notable backers. The company's early work focused on developing large language models with a strong emphasis on interpretability and alignment.
Product Development and Release
In the summer of 2022, Anthropic completed training on the first version of Claude, its flagship large language model. However, the company delayed its public release until March 2023, citing the need for further internal safety testing and a desire to avoid contributing to a potentially hazardous race in AI development. Claude was initially released with limited availability, and over time, Anthropic expanded its offerings to include multiple tiers: Haiku, Sonnet, Opus, and Fable. These models are accessible via an online chatbot, an API, and agent harnesses such as Claude Code, Cowork, Design, and Science.
In May 2025, Anthropic announced Claude 4, a major update to its model family, along with new API capabilities, including the Model Context Protocol (MCP) connector. The company also hosted its inaugural developer conference that month and launched a web search API that enables Claude to access real-time information from the internet. Additionally, Claude Code, Anthropic's coding assistant, transitioned from research preview to general availability.
Series E Funding Details
The $3.5 billion Series E round, led by Lightspeed, was announced in 2025, with the valuation of $61.5 billion. This round followed earlier funding rounds that had already established Anthropic as a major player in the AI industry. The investment was part of a trend of large funding rounds in the AI sector, with companies like OpenAI and Google DeepMind also attracting significant capital. Lightspeed's leadership in the round signaled strong investor confidence in Anthropic's technology and business model.
The funds from the Series E were earmarked for several purposes, including expanding Anthropic's compute capacity, which is critical for training and deploying large language models. The company had previously announced partnerships with cloud providers, such as Amazon Web Services and Google Cloud, to secure access to computational resources. The Series E funding was expected to accelerate these efforts and support Anthropic's research into AI safety and alignment.
Strategic Partnerships and Government Contracts
In July 2025, Anthropic signed a two-year contract with the US Department of Defense (DoD) valued at $200 million. This contract integrated Anthropic's large language models with the Pentagon's classified intelligence networks and with Palantir's data platform. Anthropic stipulated that the Pentagon not use its technologies for mass surveillance of Americans or to create fully autonomous weapons. Dario Amodei clarified that Anthropic supports the use of AI in lawful foreign intelligence and counterintelligence missions, as well as partially autonomous weapons, such as those used in the Russo-Ukrainian war.
In September 2025, Anthropic announced it would stop selling its products to groups majority-owned by Chinese, Russian, Iranian, or North Korean entities due to national security concerns. This decision reflected the company's focus on responsible AI deployment and its commitment to avoiding misuse of its technology.
Expansion and Compute Capacity
In October 2025, Anthropic announced a cloud partnership with Google Cloud, giving it access to up to one million of Google's custom Tensor Processing Units (TPUs), potentially adding more than one gigawatt of AI compute capacity by 2026. This partnership was part of Anthropic's strategy to secure the massive computational resources needed for training advanced AI models. In November 2025, Nvidia and Microsoft were expected to invest up to $15 billion in Anthropic, and Anthropic said it would buy $30 billion of computing capacity from Microsoft Azure running on Nvidia AI systems.
In December 2025, Anthropic acquired Bun, a JavaScript runtime, to improve Claude Code's speed and stability. The same month, the company signed a multi-year, $200 million partnership with Snowflake Inc. to make Claude models available through that company's platform. These moves highlighted Anthropic's efforts to expand its ecosystem and integrate its AI models into various software environments.
Controversies and Legal Issues
Anthropic has faced several controversies related to its training data and government use. Before Project Panama, an internal effort described as an "effort to destructively scan all the books in the world," Anthropic downloaded pirated books and was sued by authors. In 2025, the company settled a copyright infringement lawsuit for $1.5 billion. This settlement was one of the largest in the AI industry and underscored the legal challenges associated with training large language models on copyrighted material.
In February 2026, Anthropic aired two commercials during Super Bowl LX as part of a marketing campaign called "A Time and a Place," with four ads created by Mother. The ads depicted AI assistants suddenly pivoting to promoting a fictional product in the middle of a conversation. Anthropic said that Claude will stay ad-free, in contrast to its competitor OpenAI, which introduced ads to the free version of ChatGPT. The same month, Anthropic donated $20 million to Public First Action, an AI regulation advocacy group.
Government Dispute and National Security
In 2026, Anthropic refused the US Department of Defense's demand to remove contractual restrictions prohibiting the use of its AI technology for surveillance and autonomous weapons. After the refusal, the DoD designated the company a "supply chain risk" and barred all US military private contractors, suppliers, and partners from doing business with the firm. This dispute, known as the Anthropic–United States Department of Defense dispute, led to a federal judge blocking the phase-out of Anthropic products from government use, calling it "First Amendment retaliation."
During the 2026 Iran war, the US military used Claude to identify and rank targets in Iran according to their strategic importance, to generate strike sequences, and to write legal justifications for the strikes. This use of AI in military operations raised ethical questions about the role of AI in warfare, but Anthropic maintained that its technology was used in accordance with its policies.
Ongoing Developments and Future Outlook
In May 2026, Anthropic announced a deal with xAI for use of its Colossus 1 data center to expand its model capacity. On May 18, the company acquired software startup Stainless for an undisclosed sum. These developments indicated Anthropic's continued growth and its efforts to enhance its infrastructure and product offerings. As of 2026, Anthropic was valued at $965 billion in a Series H funding round, making it one of the world's most valuable AI pure-play companies, rivaled by OpenAI.
Throughout 2026, Anthropic accused Chinese competitors, including DeepSeek, Moonshot AI, Alibaba Cloud, and Z.ai, of distilling Claude for their models. In February 2026, Anthropic alleged that these companies generated over 16 million chats with Claude using around 24,000 fraudulent accounts, which were then used as training data. In June 2026, Anthropic accused Alibaba Cloud of similar practices. These accusations highlighted the competitive tensions in the global AI industry and the challenges of protecting proprietary technology.
Anthropic's research continues to focus on mechanistic interpretability, safety, alignment, and societal impact. Notable researchers at the company include Andrej Karpathy, John Jumper, Jan Leike, Chris Olah, and Amanda Askell. The company's commitment to AI safety and its distinctive approach to model development have positioned it as a key player in the AI landscape, with significant implications for the future of artificial intelligence.