ATEX · Anterix Inc. · Insider Trading

The option shares vest and become exercisable in three equal annual installments beginning on October 4, 2025

The sale of shares was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 22, 2026.

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 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 $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 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 $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 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 shares were withheld by the Issuer to satisfy withholding obligations in connection with the partial vesting and settlement of restricted stock units.

The shares were withheld by the Issuer to satisfy withholding obligations in connection with the partial vesting and settlement of restricted stock units.

This Form 4 is being amended to indicate that the transaction reported herein was effected pursuant to a Rule 10b5-1(c) 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 $84.25 to $83.55, 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 $84.468 to $84.00, 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 shares were withheld by the Issuer to satisfy withholding obligations in connection with the partial vesting and settlement of restricted stock units.

The Reporting Person exercised a stock option to purchase 6,833 shares of the Issuer's Common Stock for $34.96 per share and paid the exercise price on a cashless basis, resulting in the Issuer withholding an aggregate of 2,769 shares of the Issuer's Common Stock subject to the stock option to pay the exercise price and to satisfy its income tax withholding and remittance obligations in connection with the exercise of the stock option. The withholding of shares referenced here does not involve an open market sale of stock.

The option shares subject to this option shall vest and become exercisable in three equal annual installments, with 1/3 of the option shares vesting and becoming exercisable on May 20, 2026, and with the remaining option shares vesting and becoming exercisable in 2 equal annual installments thereafter.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $88.00 to $87.00, 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 $87.30 to $87.00, 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 $94.215 to $93.27, 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 Reporting Person exercised a stock option to purchase 40,000 shares of the Issuer's Common Stock for $37.42 per share and paid the exercise price on a cashless basis, resulting in the Issuer withholding an aggregate of 16,561 shares of the Issuer's Common Stock subject to the stock option to pay the exercise price and to satisfy its income tax withholding and remittance obligations in connection with the exercise of the stock option. The withholding of shares referenced here does not involve an open market sale of stock.

The option shares are fully vested.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.01 to $90.06, 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 $92.205 to $91.22, 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 $93.265 to $92.265, 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 $89.79 to $90.51, inclusive. The Reporting Person has provided to the Issuer and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $88.71 to $89.67, inclusive. The Reporting Person has provided to the Issuer and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range.

1/3rd of the option shares vest and become exercisable on January 2, 2025, with the remaining option shares vesting in two equal annual installments thereafter.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.67 to $88.66, inclusive. The Reporting Person has provided to the Issuer and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range.

Represents a charitable donation of shares to a Donor Advised Fund.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.9942 to $90.115, 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.

These securities are held by certain investment funds and/or accounts for which Heard Capital LLC serves as investment manager. The Reporting Person is the ultimate beneficial owner of Heard Capital LLC. Each of Heard Capital LLC and the Reporting Person disclaims beneficial ownership of the securities to which this filing relates for purposes of Section 16 of the Securities and Exchange Act of 1934, as amended, except to the extent of his or its pecuniary interest therein.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.515 to $88.525, 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 $91.62 to $90.665, 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 $90.66 to $89.66, 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 Shares will vest on the earlier of the 2027 Annual Meeting of shareholders and August 4, 2027, subject to the terms of the Restricted Stock Agreement.

The Shares will vest on the earlier of the 2027 Annual Meeting of shareholders and August 4, 2027, subject to the terms of the Restricted Stock Agreement.

The Shares will vest on the earlier of the 2027 Annual Meeting of shareholders and August 4, 2027, subject to the terms of the Restricted Stock Agreement.

The shares of Common Stock will vest on the earlier of the 2027 Annual Meeting of shareholders and August 4, 2027, subject to the terms of the Restricted Stock Agreement.

Represents securities granted to Jeffrey Altman ("Mr. Altman" or the "Reporting Person") as compensation for his services as a non-employee director on the Issuer's board of directors. Mr. Altman may be deemed to hold the securities reported herein for the benefit of certain funds (the "Owl Creek Funds") to which Owl Creek Asset Management, L.P., a Delaware limited partnership (the "Investment Manager"), serves as investment manager.

Each of the Investment Manager and Mr. Altman disclaims beneficial ownership of the securities to which this filing relates for purposes of Section 16 of the Securities and Exchange Act of 1934, as amended, except to the extent of his or its pecuniary interest therein, if any.

The Shares will vest on the earlier of the 2027 Annual Meeting of shareholders and August 4, 2027, subject to the terms of the Restricted Stock Agreement.

The shares were withheld by the Issuer to satisfy withholding obligations in connection with the partial vesting and settlement of restricted stock units.

The shares were withheld by the Issuer to satisfy withholding obligations in connection with the partial vesting and settlement of restricted stock units.

These shares of Common Stock were automatically sold in a non-discretionary transaction to cover tax withholding obligations upon the settlement of certain time-based RSU awards.