X0609 4 2026-10-09 0 0001304492 Anterix Inc. ATEX 0002090789 Marquez Elena false 3 GARRET MOUNTAIN PLAZA, SUITE 401 WOODLAND PARK NJ 07424 0 1 0 0 Chief Financial Officer 1 Common Stock 2026-10-09 4 S 0 3254 80.1627 D 13104 D Common Stock 2026-10-09 4 S 0 400 81.80 D 12704 D Common Stock 2026-10-09 4 S 0 100 82.50 D 12604 D Common Stock 2026-10-09 4 M 0 1227 40 A 13831 D Common Stock 2026-10-09 4 S 0 1017 80.2247 D 12814 D Common Stock 2026-10-09 4 S 0 210 81.8993 D 12604 D Stock Option (Right to Buy) 40 2026-10-09 4 M 0 1227 0 D 2035-04-03 Common Stock 1227 1227 D The sale of shares was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 22, 2026. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.00 to $80.53, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of securities sold at each separate price within the ranges set forth in this footnote to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $81.45 to $82.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of securities sold at each separate price within the ranges set forth in this footnote to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $81.765 to $82.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of securities sold at each separate price within the ranges set forth in this footnote to this Form 4. The option shares vest and become exercisable in three equal annual installments beginning on October 4, 2025 /s/ Gena L. Ashe, Attorney-in-Fact 2026-10-09