Alector Inc
Ownership
Ownership Structure
Who owns Alector Inc (ALEC)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 73.4% of the shares are freely tradable; institutional investors hold 82.3%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| TCG Crossover Management, LLC | 8.96 | 10,000,000 | +0.0 | 06/30/2026 |
| Nantahala Capital Management, LLC | 7.73 | 8,636,218 | +206.7 | 06/30/2026 |
| BlackRock Inc | 7.03 | 7,847,879 | +1.4 | 06/30/2026 |
| Acadian Asset Management LLC | 3.95 | 4,414,345 | +9.3 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.59 | 4,009,340 | +9.0 | 06/30/2026 |
| Kynam Capital Management, LP | 3.41 | 3,808,494 | +90.4 | 06/30/2026 |
| Merck & Co Inc | 3.18 | 3,545,719 | +0.0 | 06/30/2026 |
| Balyasny Asset Management LLC | 2.91 | 3,247,426 | +10.6 | 06/30/2026 |
| 683 Capital Management LLC | 2.87 | 3,200,000 | -4.5 | 03/31/2026 |
| D. E. Shaw & Co LP | 2.65 | 2,959,983 | -11.2 | 06/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Rosenthal Arnon | Chief Executive Officer | 3,514,600 | 7,732,120 $ | Aug 19, 2026 | both |
| Berkley Neil Lindsay | CFO & Chief Business Officer | 395,216 | 869,475 $ | Oct 14, 2026 | direct |
| Wong-Sarad Grace | Principal Accounting Officer | 161,570 | 355,454 $ | Oct 14, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Oct 14, 2026 | Rosenthal Arnon | Chief Executive Officer | Other | 217,500 | 0.00 | – |
| Oct 14, 2026 | Berkley Neil Lindsay | CFO & Chief Business Officer | Other | 44,567 | 0.00 | – |
| Oct 14, 2026 | Wong-Sarad Grace | Principal Accounting Officer | Other | 55,555 | 0.00 | – |
| Sep 4, 2026 | Wong-Sarad Grace | Principal Accounting Officer | Sell | 3,625 | 2.51 | 9,094 |
| Sep 3, 2026 | Wong-Sarad Grace | Principal Accounting Officer | Sell | 5,165 | 2.67 | 13,767 |
| Sep 3, 2026 | Rosenthal Arnon | Chief Executive Officer | Sell | 72,606 | 2.66 | 193,473 |
| Sep 3, 2026 | Berkley Neil Lindsay | CFO & Chief Business Officer | Sell | 29,251 | 2.66 | 77,948 |
| Sep 2, 2026 | Wong-Sarad Grace | Principal Accounting Officer | Sell | 656 | 2.75 | 1,804 |
| Aug 19, 2026 | Rosenthal Arnon | Chief Executive Officer | Other | 350,000 | 0.00 | – |
| Aug 19, 2026 | Rosenthal Arnon | Chief Executive Officer | Other | 1,050,000 | 0.00 | – |
| Jul 9, 2026 | Wong-Sarad Grace | Principal Accounting Officer | Other | 20,000 | 0.00 | – |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: October 30, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.