X0202 SCHEDULE 13G/A 0000019617 XXXXXXXX LIVE 1 Common Stock, par value $0.01 per share 10/30/2026 0000866291 ALLEGRO MICROSYSTEMS, INC. 01749D105 955 Perimeter Road Manchester NH 03103 Rule 13d-1(b) JPMORGAN CHASE & CO. DE 7496819.0 1.0 8022623.0 237.0 8022860.0 4.3 HC ALLEGRO MICROSYSTEMS, INC. 955 Perimeter Road Manchester NH 03103 JPMORGAN CHASE & CO. 270 Park Avenue,,New York, NY 10017 DE N HC 8022860 4.3 7496819 1 8022623 237 N Y N Not Applicable N J.P. Morgan Trust Company of Delaware; J.P. Morgan Securities LLC; JPMorgan Asset Management (UK) Limited; JPMorgan Chase Bank, National Association; J.P. Morgan Investment Management Inc.; J.P. Morgan Wealth Management Solutions Inc.; 55I, LLC N Not Applicable N Not Applicable N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and 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. JPMORGAN CHASE & CO. Rachel Tsvaygoft 11/05/2026