SEC Filing Summary

On June 2, 2026, Arnon Rosenthal, Chief Executive Officer of Alector, Inc., reported a disposition of 87,216 shares of Common Stock. The transaction, coded as 'S', resulted in a disposal of shares with a weighted average price of $1.9743 per share. This sale was conducted to cover tax obligations related to the vesting of restricted stock units. Following this transaction, Mr. Rosenthal's post-transaction shares amount to 2,367,206. The reported securities are held indirectly through various trusts, including The Rosenthal Family Revocable Trust, the Adi Rosenthal 2007 Trust, the Noam Rosenthal 2007 Trust, and the Shani Rosenthal 2007 Trust. The filing also details Mr. Rosenthal's direct and indirect ownership stakes in Alector, Inc. subsequent to the transaction.