Lightspeed Venture Partners is raising roughly $600 million through a secondary transaction that extends its position in OpenAI, deepens its commitment to Anthropic, and maintains stakes in three other portfolio companies, according to reporting on the deal structure announced August 12.
The transaction, known as Project Mercury, is a continuation vehicle that allows the Sand Hill Road firm to manage concentrated bets in private artificial intelligence companies without forcing exits. Lightspeed holds early stakes in both OpenAI and Anthropic, two of the three most-capitalized AI labs globally. The secondary structure lets the firm commit fresh capital to Anthropic while holding its OpenAI position, the opposite of an offload.
The five named holdings in the transaction are OpenAI, Anthropic, Verkada (which makes physical security cameras), Rippling (HR software), and Glean (enterprise search). Lightspeed did not publicly disclose the specific allocation across companies or the per-company valuations underpinning the $600 million raise.
Secondary transactions for private stakes have become standard at mega-funds managing exposure to companies that remain private well into scale. Existing limited partners in a fund can sell their stakes to new or existing LPs via the continuation vehicle rather than waiting for an exit event. The structure also allows Lightspeed to hold AI positions through multiple funding rounds rather than harvest gains at each round close.
Lightspeed is one of the oldest venture firms to have invested in both OpenAI and Anthropic. The firm backed OpenAI in its Series B round in 2021 and participated in early Anthropic funding. Both companies have since raised at nine-figure valuations, OpenAI last at $157 billion in October 2024, Anthropic most recently at $60 billion in July 2026. The secondary deal lets Lightspeed maintain its ownership while managing fund-level capital allocation.
Raising $600 million for a single continuation vehicle is larger than most sector-specific secondaries but modest relative to Lightspeed's main fund sizes, which have topped $1 billion in recent vintages. The firm manages roughly $15 billion in assets under management across all vehicles. The deal comes as venture firms now compete for access to AI company stakes at later stages, when primary-round availability has tightened for larger checks.
Lightspeed's ability to raise $600 million on the strength of OpenAI and Anthropic stakes alone shows how heavily these two companies weigh in venture portfolios. A $600 million secondary raise on five companies averages $120 million per holding, though allocation across the five likely skews heavily toward the two AI labs. If the OpenAI and Anthropic combined stake represents 70 percent of the vehicle, the two positions alone would anchor roughly $420 million in committed capital.
The number that decides whether this secondary gains traction is whether Lightspeed completes the full $600 million commitment by the fund's close date; continuation vehicles typically have hard deadlines for LP subscriptions, and shortfalls can indicate diminished appetite for the underlying positions.
