AlphaMaven AlphaMaven

Andreessen Horowitz funds trim Nautilus (NAUT) stake with 5M-share open-market sale

Reported by stocktitan
Jun 4, 2026· 2 min read
Save Post LinkedIn Email
Key Takeaways
  • • Andreessen Horowitz funds executed an open-market sale of 5 million shares of Nautilus Biotechnology (NASDAQ: NAUT), reducing their stake from approximately 14% to near 10% of common stock.
  • • The sale represents a significant partial exit by the venture capital firm, which led Nautilus's Series A and has maintained board representation since the company's 2021 Nasdaq listing.
  • • Nautilus Biotechnology is a proteomics-focused biotech company that completed its public debut in June 2021 via SPAC merger with Arya Sciences Acquisition Corporation, raising approximately $345 million in gross proceeds.
  • • The stake reduction comes amid mixed market conditions for the biotech sector, including a Goldman Sachs downgrade of NAUT from Neutral to Sell in recent trading activity.
  • • Nautilus remains focused on commercializing its Voyager proteomics platform following 10 years of R&D investment totaling approximately $350 million.
Summary
Andreessen Horowitz has trimmed its investment in Nautilus Biotechnology through an open-market sale of 5 million shares, according to regulatory disclosures. The transaction reduces the venture capital firm's ownership stake from approximately 14% of the company's common stock to near 10%, marking a partial but material reduction in AH Capital Management's position in the Seattle-based proteomics company.

Andreessen Horowitz has been a foundational investor in Nautilus since leading the company's Series A funding round and subsequently participating in the Series B with Madrona Venture Group. The firm secured board representation through its involvement in Nautilus's early development and maintained that position through the company's path to public markets. Nautilus completed its Nasdaq listing in June 2021 as a publicly traded company following a SPAC merger with Arya Sciences Acquisition Corporation, which generated approximately $345 million in gross proceeds to fund the company's next phase of growth.

Nautilus Biotechnology operates in the high-stakes proteomics sector, focusing on mass spectrometry-based protein analysis platforms. The company has invested approximately $350 million in research and development over the past decade to develop its proprietary Voyager platform, which represents its primary commercial offering. CEO Sujal Patel continues to hold approximately 14% of the company's common stock, maintaining significant alignment with other major investors including Perceptive Advisors, Madrona Venture Group, and Amazon as a shareholder.

The stake reduction by Andreessen Horowitz occurs in a challenging environment for Nautilus equity, evidenced by a recent Goldman Sachs downgrade from Neutral to Sell. Such insider sales by major institutional shareholders are closely monitored by market participants for signals regarding management confidence and capital allocation priorities within the biotech sector.

Go deeper than the headline

Research every firm in this story, track the ones that matter and get the daily briefing — free for 7 days.

Start your free 7-day trial