SCHEDULE 13G/A 0001224962 XXXXXXXX LIVE 13 Common Stock, par value $0.001 per share 06/30/2025 0001341235 Aldeyra Therapeutics, Inc. 01438T106 131 Hartwell Avenue Suite 320 Lexington MA 02421 Rule 13d-1(c) Perceptive Advisors LLC DE 0 4051631 0 4051631 4051631 N 6.8 IA Joseph Edelman X1 0 4051631 0 4051631 4051631 N 6.8 IN Perceptive Life Sciences Master Fund, Ltd. E9 0 4051631 0 4051631 4051631 N 6.8 CO Aldeyra Therapeutics, Inc. 131 Hartwell Avenue, Suite 320,Lexington, MA 02421 The names of the persons filing this report (collectively, the "Reporting Persons") with respect to shares of Common Stock, par value $0.001 per share (the "Common Stock") of Aldeyra Therapeutics, Inc. ("the Issuer") are: (i) Perceptive Advisors LLC ("Perceptive Advisors") (ii) Joseph Edelman ("Mr. Edelman") (iii) Perceptive Life Sciences Master Fund, Ltd. (the "Master Fund") The address of the principal business office of each of the Reporting Persons is: 51 Astor Place, 10th Floor, New York, NY 10003 Perceptive Advisors is a Delaware limited liability company. Mr. Edelman is a United States citizen. The Master Fund is a Cayman Islands corporation. Y The information required by this item with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of the cover pages to this Schedule 13G. The ownership percentages reported are based on 59,895,588 outstanding shares of Common Stock as of August 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 7, 2025. The Master Fund directly holds 4,051,631 shares of Common Stock. Perceptive Advisors serves as the investment manager to the Master Fund and may be deemed to beneficially own such shares. Mr. Edelman is the managing member of Perceptive Advisors and may be deemed to beneficially own such shares. Perceptive Advisors: 6.8% Mr. Edelman: 6.8% Master Fund, Ltd: 6.8% Perceptive Advisors: 0 Mr. Edelman: 0 Master Fund: 0 Perceptive Advisors: 4,051,631 Mr. Edelman: 4,051,631 Master Fund: 4,051,631 Perceptive Advisors: 0 Mr. Edelman: 0 Master Fund: 0 Perceptive Advisors: 4,051,631 Mr. Edelman: 4,051,631 Master Fund: 4,051,631 Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Perceptive Advisors LLC /s/ Joseph Edelman 08/14/2025 Joseph Edelman /s/ Joseph Edelman 08/14/2025 Perceptive Life Sciences Master Fund, Ltd. /s/ Joseph Edelman 08/14/2025