Anthropic raises $750M Series D

Anthropic raised $750 million in a round that quadrupled its valuation to $18.4 billion, first reported by CNBC as in-progress talks in December 2023 and confirmed via a regulatory filing the following January. Neither Anthropic nor its lead investor issued a press release; the deal became public through a Securities and Exchange Commission filing and reporting that followed it, including from Forbes and The Information.

The round’s structure was unusual for its lead, Menlo Ventures. Rather than writing the check from its existing venture fund, Menlo raised a dedicated special-purpose vehicle, Menlo Inflection AI Partners, to supply roughly $500 million of the total, with the remaining $250 million coming from Menlo’s own fund and from firm insiders. Forbes reported that Amazon and Google, already Anthropic investors, held further tranches of committed capital available to deploy separately from this round. Menlo had previously participated in Anthropic’s Series C.

Later coverage, including a TechCrunch retrospective published after Menlo raised its own $3 billion fund on the strength of the position, described Menlo as “preemptively leading the model maker’s Series D” — treating the round as the fourth lettered venture round in Anthropic’s sequence, following Series B and Series C, notwithstanding that neither Anthropic nor Menlo used the label at the time of the deal itself. The round came roughly three months after Amazon’s and Google’s separate multi-billion-dollar strategic commitments that September and October, underscoring how much of Anthropic’s rising valuation through late 2023 and early 2024 was being set by its existing corporate backers rather than by new entrants to its cap table.