ALECNasdaqBiological Products, (No Diagnostic Substances)Fiscal year ends December 31
Alector, Inc.
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Aug 6, 2026
$1.95+0.11 (+5.98%)
Close on Oct 19, 2026
- Market cap
- $216.89M
- P/E (TTM)
- –
- Dividend yield
- –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
85.8%
96M of 112M shares
Institutional holders
141
14 new, 9 sold out
Net institutional buying
7M
In Q2 2026
Insider trades, 12 months
0 buys · 21 sales
Net sold $1.02M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Lampert Mark N | 9,374,267 | 8.40% | 13G (passive) | Sep 11, 2026 |
| Arnon Rosenthal | 8,213,925 | 7.40% | 13G (passive) amendment | Dec 31, 2025 |
| RTW Investments, LP | 6,990,806 | 6.90% | 13G (passive) | Sep 30, 2025 |
| BlackRock, Inc. | 5,784,214 | 5.20% | 13G (passive) | Mar 31, 2026 |
| Chen Yu | 10,000,000 | 9.20% | 13G (passive) | Oct 22, 2025 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of ALEC | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| TCG Crossover Management, LLC | 10,000,000 | 8.96% | $20.10M | – | 0.48% |
| Nantahala Capital Management, LLC | 8,636,218 | 7.73% | $17.36M | +5,820,235 | 0.29% |
| BlackRock, Inc. | 7,847,879 | 7.03% | $15.77M | +106,634 | 0.00% |
| Acadian Asset Management LLC | 4,414,345 | 3.95% | $8.86K | +375,560 | 0.01% |
| Vanguard Capital Management LLC | 4,009,340 | 3.59% | $8.06M | +330,618 | 0.00% |
| Kynam Capital Management, LP | 3,808,494 | 3.41% | $7.66M | +1,808,494 | 0.42% |
| Merck & Co., Inc. | 3,545,719 | 3.18% | $7.13M | – | 1.35% |
| Balyasny Asset Management L.P. | 3,247,426 | 2.91% | $6.53M | +312,173 | 0.01% |
| 683 Capital Management, LLC | 3,200,000 | 2.87% | $6.43M | – | 0.32% |
| D. E. Shaw & Co., Inc. | 2,959,983 | 2.65% | $5.95M | −372,852 | 0.00% |
| ADAR1 Capital Management, LLC | 2,883,583 | 2.58% | $5.80M | +1,833,583 | 0.27% |
| Vanguard Portfolio Management LLC | 2,820,493 | 2.53% | $5.67M | +236,951 | 0.00% |
| Geode Capital Management, LLC | 2,454,271 | 2.20% | $4.93M | +168,053 | 0.00% |
| Spruce Street Capital LP | 2,101,068 | 1.88% | $4.22M | – | 0.83% |
| Millennium Management LLC | 1,988,835 | 1.78% | $4.00M | +9,609 | 0.00% |
| Ikarian Capital, LLC | 1,982,606 | 1.78% | $3.99M | −100,000 | 0.43% |
| State Street Corp | 1,879,765 | 1.68% | $3.78M | +14,239 | 0.00% |
| Jacobs Levy Equity Management, Inc | 1,765,929 | 1.58% | $3.55M | −388,432 | 0.01% |
| Medici Capital LLC | 1,652,520 | 1.48% | $3.32M | – | 6.51% |
| Affinity Asset Advisors, LLC | 1,510,000 | 1.35% | $3.04M | +1,010,000 | 0.14% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 141 | 96M | 85.8% | 14 / 59 | 35 / 9 | 15M | 8M |
| Q1 2026 | 138 | 88M | 79.2% | 29 / 43 | 37 / 20 | 17M | 6M |
| Q4 2025 | 131 | 85M | 75.7% | 25 / 41 | 40 / 39 | 38M | 28M |
| Q3 2025 | 149 | 75M | 67.1% | 25 / 45 | 41 / 12 | 14M | 10M |
| Q2 2025 | 136 | 71M | 63.5% | 17 / 47 | 38 / 22 | 13M | 15M |
| Q1 2025 | 141 | 73M | 65.1% | 20 / 46 | 33 / 28 | 4M | 5M |
| Q4 2024 | 150 | 73M | 65.8% | 31 / 46 | 38 / 39 | 20M | 22M |
| Q3 2024 | 159 | 75M | 67.4% | 20 / 48 | 50 / 19 | 16M | 6M |
| Q2 2024 | 160 | 74M | 66.7% | 24 / 58 | 50 / 19 | 8M | 16M |
| Q1 2024 | 157 | 83M | 73.9% | 28 / 61 | 35 / 17 | 15M | 3M |
| Q4 2023 | 148 | 70M | 63.1% | 16 / 49 | 49 / 15 | 13M | 6M |
| Q3 2023 | 148 | 63M | 56.7% | 20 / 59 | 40 / 17 | 11M | 6M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
| Fund | Shares | % of ALEC | Value | % of fund | As of |
|---|---|---|---|---|---|
| Vanguard Total Stock Market Index Fund | 2,837,922 | 2.54% | $5.70M | 0.00% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 2,548,224 | 2.28% | $5.12M | 0.01% | Jun 30, 2026 |
| Select Biotechnology Portfolio | 1,380,204 | 1.24% | $2.98M | 0.06% | May 31, 2026 |
| Fidelity Small Cap Index Fund | 1,067,159 | 0.96% | $1.61M | 0.00% | Jul 31, 2026 |
| Vanguard Extended Market Index Fund | 1,033,776 | 0.93% | $2.08M | 0.00% | Jun 30, 2026 |
| iShares Russell 2000 Growth ETF | 820,921 | 0.74% | $1.65M | 0.01% | Jun 30, 2026 |
| Vanguard Explorer Fund | 673,493 | 0.60% | $1.02M | 0.00% | Jul 31, 2026 |
| BlackRock Advantage Small Cap Core Fund | 635,411 | 0.57% | $1.37M | 0.03% | May 29, 2026 |
| Vanguard Strategic Small-Cap Equity Fund | 628,627 | 0.56% | $1.26M | 0.04% | Jun 30, 2026 |
| Small Company Growth Portfolio | 615,923 | 0.55% | $1.24M | 0.07% | Jun 30, 2026 |
| Fidelity Extended Market Index Fund | 484,110 | 0.43% | $1.05M | 0.00% | May 31, 2026 |
| Vanguard Russell 2000 Index Fund | 468,899 | 0.42% | $1.01M | 0.01% | May 31, 2026 |
| Schwab U.S. Small-Cap ETF | 441,696 | 0.40% | $954.06K | 0.00% | May 31, 2026 |
| iShares Micro-Cap ETF | 330,159 | 0.30% | $663.62K | 0.04% | Jun 30, 2026 |
| Schwab Small-Cap Index Fund | 239,291 | 0.21% | $361.33K | 0.00% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Arnon Rosenthal | Chief Executive Officer, Director | 3,297,100 | 2.95% | Sep 4, 2026 |
| Grace Wong-Sarad | Principal Accounting Officer | 106,015 | 0.09% | Sep 4, 2026 |
| Neil Lindsay Berkley | CFO & Chief Business Officer | 350,649 | 0.31% | Sep 4, 2026 |
| Sara Kenkare-Mitra | President and Head of R&D | 501,652 | 0.45% | Dec 3, 2025 |
| Marc Grasso | Chief Financial Officer | 296,072 | 0.27% | Jun 4, 2025 |
| Gary Romano | Chief Medical Officer | 332,977 | 0.30% | Mar 5, 2025 |
| Elizabeth A. Garofalo | Director | 118,650 | 0.11% | Jun 17, 2026 |
| Mark Altmeyer | Director | 98,650 | 0.09% | Jun 17, 2026 |
| Errol B. Desouza | Director | 98,650 | 0.09% | Jun 17, 2026 |
| Louis J. Lavigne Jr | Director | 138,661 | 0.12% | Jun 17, 2026 |
| Richard H. Scheller | Director | 134,899 | 0.12% | Jun 17, 2026 |
| Kristine Yaffe | Director | 124,109 | 0.11% | Jun 17, 2026 |
| Paula Hammond | Director | 103,609 | 0.09% | Jun 17, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Grace Wong-Sarad Principal Accounting Officer | Sep 4, 2026 | Sale(10b5-1 plan) | −3,625 | $2.51 | $9.10K | 106,015 |
| Grace Wong-Sarad Principal Accounting Officer | Sep 3, 2026 | Sale(10b5-1 plan) | −5,165 | $2.67 | $13.79K | 109,640 |
| Neil Lindsay Berkley CFO & Chief Business Officer | Sep 3, 2026 | Sale | −29,251 | $2.66 | $77.81K | 350,649 |
| Arnon Rosenthal Chief Executive Officer, Director | Sep 3, 2026 | Sale | −72,606 | $2.66 | $193.13K | 2,294,600 |
| Grace Wong-Sarad Principal Accounting Officer | Sep 2, 2026 | Sale(10b5-1 plan) | −656 | $2.75 | $1.80K | 114,805 |
| Arnon Rosenthal Chief Executive Officer, Director | Aug 19, 2026 | Gift | +350,000 | – | – | 1,002,500 |
| Arnon Rosenthal Chief Executive Officer, Director | Aug 19, 2026 | Gift | +350,000 | – | – | 1,002,500 |
| Arnon Rosenthal Chief Executive Officer, Director | Aug 19, 2026 | Gift | −1,050,000 | – | – | 922,875 |
| Arnon Rosenthal Chief Executive Officer, Director | Aug 19, 2026 | Gift | +350,000 | – | – | 1,002,500 |
| Grace Wong-Sarad Principal Accounting Officer | Jul 9, 2026 | Award | +20,000 | – | – | 115,461 |
| Mark Altmeyer Director | Jun 17, 2026 | Award | +28,700 | – | – | 98,650 |
| Elizabeth A. Garofalo Director | Jun 17, 2026 | Award | +28,700 | – | – | 118,650 |
| Errol B. Desouza Director | Jun 17, 2026 | Award | +28,700 | – | – | 98,650 |
| Kristine Yaffe Director | Jun 17, 2026 | Award | +28,700 | – | – | 124,109 |
| Richard H. Scheller Director | Jun 17, 2026 | Award | +28,700 | – | – | 134,899 |
| Paula Hammond Director | Jun 17, 2026 | Award | +28,700 | – | – | 103,609 |
| Louis J. Lavigne Jr Director | Jun 17, 2026 | Award | +28,700 | – | – | 128,109 |
| Grace Wong-Sarad Principal Accounting Officer | Jun 3, 2026 | Sale(10b5-1 plan) | −3,475 | $1.88 | $6.53K | 95,461 |
| Arnon Rosenthal Chief Executive Officer, Director | Jun 2, 2026 | Sale | −87,216 | $1.97 | $171.82K | 2,367,206 |
| Neil Lindsay Berkley CFO & Chief Business Officer | Jun 2, 2026 | Sale | −19,360 | $1.97 | $38.14K | 379,900 |
| Grace Wong-Sarad Principal Accounting Officer | Jun 2, 2026 | Sale(10b5-1 plan) | −5,709 | $1.97 | $11.25K | 98,936 |
| Richard H. Scheller Director | Jun 1, 2026 | Award | +10,833 | – | – | 106,199 |
| Grace Wong-Sarad Principal Accounting Officer | Apr 16, 2026 | Sale(10b5-1 plan) | −1,820 | $2.65 | $4.82K | 104,645 |
| Neil Lindsay Berkley CFO & Chief Business Officer | Mar 15, 2026 | Award | +54,600 | – | – | 399,260 |
| Arnon Rosenthal Chief Executive Officer, Director | Mar 13, 2026 | Award | +116,246 | – | – | 2,454,422 |
| Grace Wong-Sarad Principal Accounting Officer | Mar 10, 2026 | Sale(10b5-1 plan) | −1,000 | $2.65 | $2.65K | 106,465 |
| Grace Wong-Sarad Principal Accounting Officer | Mar 3, 2026 | Sale(10b5-1 plan) | −3,367 | $2.08 | $7.00K | 107,465 |
| Arnon Rosenthal Chief Executive Officer, Director | Mar 2, 2026 | Sale | −81,864 | $2.12 | $173.55K | 2,338,176 |
| Grace Wong-Sarad Principal Accounting Officer | Mar 2, 2026 | Sale | −8,071 | $2.12 | $17.11K | 110,832 |
| Neil Lindsay Berkley CFO & Chief Business Officer | Mar 2, 2026 | Sale | −29,649 | $2.12 | $62.86K | 344,660 |
| Grace Wong-Sarad Principal Accounting Officer | Feb 26, 2026 | Sale(10b5-1 plan) | −4,079 | $2.50 | $10.20K | 118,903 |
| Grace Wong-Sarad Principal Accounting Officer | Dec 5, 2025 | Sale(10b5-1 plan) | −4,753 | $1.21 | $5.75K | 122,982 |
| Sara Kenkare-Mitra President and Head of R&D | Dec 3, 2025 | Sale | −41,687 | $1.12 | $46.69K | 501,652 |
| Grace Wong-Sarad Principal Accounting Officer | Dec 3, 2025 | Sale | −8,056 | $1.12 | $9.02K | 127,735 |
| Neil Lindsay Berkley Chief Bus Ofcr & Interim CFO | Dec 3, 2025 | Sale | −37,261 | $1.12 | $41.73K | 374,309 |
| Arnon Rosenthal Chief Executive Officer, Director | Dec 3, 2025 | Sale | −104,347 | $1.12 | $116.87K | 2,420,040 |
| Grace Wong-Sarad Principal Accounting Officer | Nov 10, 2025 | Award | +32,343 | – | – | 135,791 |
| Neil Lindsay Berkley Chief Bus Ofcr & Interim CFO | Nov 10, 2025 | Award | +65,000 | – | – | 411,570 |
| Arnon Rosenthal Chief Executive Officer, Director | Nov 10, 2025 | Award | +174,167 | – | – | 2,524,387 |
| Grace Wong-Sarad Principal Accounting Officer | Sep 2, 2025 | Sale | −5,910 | $2.50 | $14.78K | 103,448 |
| Sara Kenkare-Mitra President and Head of R&D | Sep 2, 2025 | Sale | −23,638 | $2.50 | $59.10K | 543,339 |
| Arnon Rosenthal Chief Executive Officer, Director | Sep 2, 2025 | Sale | −51,562 | $2.50 | $128.91K | 2,350,220 |
| Neil Lindsay Berkley Principal Financial Officer | Sep 2, 2025 | Sale | −15,842 | $2.50 | $39.61K | 346,570 |
| Paula Hammond Director | Aug 26, 2025 | Sale(10b5-1 plan) | −14,000 | $2.36 | $33.04K | 74,909 |
| Sara Kenkare-Mitra President and Head of R&D | Jul 1, 2025 | Award | +54,725 | – | – | 566,977 |
| Arnon Rosenthal Chief Executive Officer, Director | Jul 1, 2025 | Award | +137,125 | – | – | 2,551,782 |
| Kristine Yaffe Director | Jun 20, 2025 | Sale(10b5-1 plan) | −1,000 | $1.44 | $1.44K | 95,409 |
| Paula Hammond Director | Jun 11, 2025 | Award | +28,700 | – | – | 88,909 |
| Elizabeth A. Garofalo Director | Jun 11, 2025 | Award | +28,700 | – | – | 89,950 |
| Errol B. Desouza Director | Jun 11, 2025 | Award | +28,700 | – | – | 69,950 |
| Kristine Yaffe Director | Jun 11, 2025 | Award | +28,700 | – | – | 96,409 |
| Mark Altmeyer Director | Jun 11, 2025 | Award | +28,700 | – | – | 69,950 |
| Louis J. Lavigne Jr Director | Jun 11, 2025 | Award | +28,700 | – | – | 99,409 |
| Richard H. Scheller Director | Jun 11, 2025 | Award | +28,700 | – | – | 95,366 |
| Sara Kenkare-Mitra President and Head of R&D | Jun 2, 2025 | Sale | −23,890 | $1.34 | $32.01K | 512,252 |
| Arnon Rosenthal Chief Executive Officer, Director | Jun 2, 2025 | Sale | −52,087 | $1.34 | $69.80K | 2,414,657 |
| Marc Grasso Chief Financial Officer | Jun 2, 2025 | Sale | −16,488 | $1.34 | $22.09K | 296,072 |
| Richard H. Scheller Director | May 2, 2025 | Award | +15,833 | – | – | 66,666 |
| Arnon Rosenthal Chief Executive Officer, Director | Mar 3, 2025 | Sale | −40,330 | $1.47 | $59.29K | 2,466,744 |
| Marc Grasso Chief Financial Officer | Mar 3, 2025 | Sale | −18,091 | $1.47 | $26.59K | 312,560 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Wong-Sarad Grace Officer | Sep 4, 2026 | 3,625 | $9.09K | Sep 4, 2026 | Restricted Stock |
| Wong-Sarad Grace Officer | Sep 2, 2026 | 656 | $1.80K | Sep 2, 2026 | Restricted Stock |
| Wong-Sarad Grace Officer | Sep 1, 2026 | 5,662 | $13.59K | Sep 2, 2026 | Vesting of Restricted Stock Units |
| Rosenthal Arnon Officer, Director | Sep 1, 2026 | 79,702 | $191.28K | Sep 2, 2026 | Vesting of Restricted Stock Units |
| L. Berkley Neil Officer | Sep 1, 2026 | 32,103 | $77.05K | Sep 2, 2026 | Vesting of Restricted Stock Units |
| Wong-Sarad Grace Officer | Jun 3, 2026 | 3,475 | $6.54K | Jun 3, 2026 | Restricted Stock |
| L. Berkley Neil Officer | Jun 1, 2026 | 18,213 | $37.70K | Jun 2, 2026 | Vesting of Restricted Stock Units |
| Wong-Sarad Grace Officer | Jun 1, 2026 | 5,239 | $10.84K | Jun 2, 2026 | Vesting of Restricted Stock Units |
| Rosenthal Arnon Officer, Director | Jun 1, 2026 | 67,572 | $139.87K | Jun 2, 2026 | Vesting of Restricted Stock Units |
| Wong-Sarad Grace Officer | Apr 16, 2026 | 1,820 | $4.82K | Apr 16, 2026 | Restricted Stock |
| Wong-Sarad Grace Officer | Mar 10, 2026 | 1,000 | $2.65K | Mar 10, 2026 | Restricted Stock |
| Wong-Sarad Grace Officer | Mar 3, 2026 | 3,367 | $7.01K | Mar 3, 2026 | Restricted Stock |
| L. Berkley Neil Officer | Feb 27, 2026 | 23,161 | $56.28K | Mar 2, 2026 | Vesting of Restricted Stock Units |
| Rosenthal Arnon Officer, Director | Feb 27, 2026 | 67,571 | $164.20K | Mar 2, 2026 | Vesting of Restricted Stock Units |
| Wong-Sarad Grace Officer | Feb 27, 2026 | 6,297 | $15.30K | Mar 2, 2026 | Vesting of Restricted Stock Units |