<div id="readability-page-1"><div><p><span>Rosenthal Arnon Chief Executive Officer of Alector Inc [ALEC] filed a Form 4 on December 3, 2025 with the Securities and Exchange Commission disclosing the following changes in ownership:</span></p><div><table><tbody><tr><td><span>Date</span></td><td><span>12/3/25</span></td></tr><tr><td><span>Transaction</span></td><td><span>Surrender(1)</span></td></tr><tr><td><span>Shares</span></td><td><span>104,347</span></td></tr><tr><td><span>Price</span></td><td><span>$1.12</span></td></tr><tr><td><span>Value</span></td><td><span>$116,827</span></td></tr></tbody></table></div><p><span>Ending Holdings: 6,350,415 (2,420,040 - Direct, 3,930,375 - Indirect)</span></p><ul><li><span>(1)</span></li><li><span>Surrender of shares back to company to pay option exercise cost and/or resulting tax liability.</span></li></ul><p><span>For a free trial, or to learn more about our insider trading analysis and data services, please visit http://www.washingtonservice.com or contact us at (301) 913-5100 or send an email to info@washingtonservice.com.</span></p><p><span>Founded in 1970, The Washington Service provides securities professionals with financial, economic and public policy research and data.</span></p><span> </span></div></div>

ALEC

<p>Rosenthal Arnon, CEO of Alector Inc [ALEC], filed a Form 4 with the SEC on December 3, 2025, disclosing the surrender of 104,347 shares at $1.12 each, valued at $116,827. The surrender was to cover option exercise costs and/or tax liabilities. Rosenthal's ending holdings are 6,350,415 shares (2,420,040 direct, 3,930,375 indirect).</p>

CEO Rosenthal Surrenders 104,347 Of Alector Inc [ALEC]