Alector, Inc. (ALEC) Institutional Ownership

Ownership Summary

Alector, Inc. (NASDAQ:ALEC) appears in 125 institutional 13F filings for the quarter ending December 2025.

• They owned 83.2% of outstanding stock in December 2025, up from 73.3% the prior quarter.
• They increased total shares held in Alector by 34.94% from the prior quarter, while the number of investors in ALEC decreased 14.38% year over year.
• Activity in ALEC broke down as 63 buyers, 41 sellers, and 21 unchanged among 125 total holders.
• In total, institutional investors held 85.37Mn shares in Alector as of December 2025, up by 22.1Mn shares quarter on quarter, and up 10.09Mn shares year over year.
• As of December 31, 2025, the biggest holder of Alector is TCG Crossover Management, LLC at 10.0Mn shares, representing 9.75% of shares outstanding.
• The most significant purchases of ALEC for the quarter ending December 2025 came from TCG Crossover Management, LLC (10.0Mn), Foresite Capital Management IV, LLC (3.89Mn), BALYASNY ASSET MANAGEMENT L.P. (3.27Mn), 683 Capital Management, LLC (2.35Mn), ADAR1 Capital Management, LLC (2.22Mn).
• Leading sellers of Alector shares for the quarter ending December 2025 were FMR LLC (12.95Mn), Royal Bank Of Canada (623.97K), Eversept Partners, LP (482.56K), Barclays Plc (474.69K), CITADEL ADVISORS LLC (378.03K).
• Business Quant data shows the 10 biggest positions in Alector as of December 2025 are held by TCG Crossover Management, LLC (10.0Mn), BlackRock, Inc. (7.15Mn), VANGUARD GROUP INC (6.91Mn), Foresite Capital Management IV, LLC (3.89Mn), Merck & Co., Inc. (3.55Mn), ACADIAN ASSET MANAGEMENT LLC (3.44Mn), 683 Capital Management, LLC (3.35Mn), BALYASNY ASSET MANAGEMENT L.P. (3.27Mn), D. E. Shaw & Co., Inc. (2.37Mn), FMR LLC (2.23Mn).