Amendment: SEC Form SCHEDULE 13D/A filed by Sphere Entertainment Co.

The disclosure in Item 2(c) is hereby amended by adding the following at the end thereof: Patrick F. Dolan is a no longer a director of AMC Networks Inc. Patrick F. Dolan is the owner and president of Newsday, Long Island's newspaper. Newsday's principal business address is 6 Corporate Center Drive, Melville, NY 11747.

The disclosure in Item 5(a) and (b) is hereby amended and supplemented as follows: (a) and (b) As of February 27, 2026, the Group Members may be deemed to beneficially own an aggregate of 8,698,719 shares of Class A Common Stock as a result of their beneficial ownership of (i) 1,831,965 shares of Class A Common Stock (inclusive of exercisable options, restricted stock units vesting within 60 days of the date hereof and shares held by the Dolan Family Foundation, for which certain Group Members serve as director), and (ii) 6,866,754 shares of Class A Common Stock issuable upon conversion of an equal number of shares of Class B Common Stock. This aggregate amount represents approximately 24.4% of the total shares of Common Stock deemed to be currently outstanding. Group Members in the aggregate may be deemed to have the current shared power to vote or direct the vote of and to dispose of or direct the disposition of 6,866,754 shares of Class A Common Stock issuable upon conversion of an equal number of shares of Class B Common Stock (representing all outstanding Class B Common Stock) because of the terms of the Class B Stockholders' Agreement (as previously defined in the Schedule 13D). Reporting Persons and individuals who are not Group Members but are trustees of trusts that are Group Members may be deemed to beneficially own an additional 58,744 shares of Class A Common Stock. Each of the Reporting Persons disclaims beneficial ownership of the securities held by the other Reporting Persons, and this report shall not be deemed to be an admission that any such person is the beneficial owner of such securities. The percentages used herein with respect to the ownership of Class A Common Stock are calculated based on 28,635,366 outstanding shares of Class A Common Stock as of January 31, 2026, as reported by the Issuer in its Annual Report on Form 10-K that was filed with the SEC on February 12, 2026. See the responses to Items 7 through 13 of each cover page to this Amendment No. 7, which are incorporated by reference. See Exhibit A for supplemental information regarding the beneficial ownership of Class A Common Stock by the Group Members and other individuals who are not Group Members but are trustees of trusts that are Group Members. See Exhibit B for additional information regarding the Reporting Persons that are trusts.

See Item 5(a) above, Exhibit A and Exhibit B.

On February 17, 2026 James L. Dolan exercised 108,630 stock options for Class A Common Stock through cashless exercise that were also settled in cash. In connection with the exercise of the stock options, 21,670 shares of Class A Common Stock were withheld to satisfy tax withholding obligations and 63,761 shares of Class A Common Stock were withheld to satisfy the exercise price. The information contained in Item 6 of this Amendment No. 7 is incorporated by reference.

The disclosure in Item 6 is hereby amended by adding the following at the end thereof: On February 25, 2026, the CFD 2009 Family Trust FBO James L. Dolan contributed 6,717 shares of Class A Common Stock of the Issuer to CFD 2009 Family Trust LLC and the Charles F. Dolan Children Trust FBO James L. Dolan contributed 44,342 shares of Class A Common Stock of the Issuer to CFD 2009 Children's Trust LLC. On February 25, 2026, James L. Dolan entered into a Secured Margin Line of Credit Note (the "Note") and each of CFD 2009 Family Trust LLC and CFD 2009 Children's Trust LLC entered into a Margin Line of Credit Collateral Agreement (the "Collateral Agreement"), in each case, with JPMorgan Chase Bank, N.A. ("JPM"). In connection therewith, James L. Dolan agreed to pledge to JPM 977,835 shares of Class A Common Stock of the Issuer, CFD 2009 Family Trust LLC agreed to pledge to JPM 6,717 shares of Class A Common Stock of the Issuer and CFD 2009 Children's Trust LLC agreed to pledge to JPM 44,342 shares of Class A Common Stock of the Issuer (all such pledged shares of Class A Common Stock collectively, the "Collateral") to secure obligations under the Note pursuant to the Note and the Collateral Agreement. Upon the occurrence of certain events that are customary with this type of transaction, JPM may exercise its rights to foreclose on, and dispose of, the Collateral in accordance with the Note and the Collateral Agreement. Copies of the Note and the Collateral Agreement are attached as Exhibits to this Schedule 13D and are incorporated herein by reference.

The disclosure in Item 7 is hereby amended by adding Exhibit A.2, Exhibit D.2, Exhibit E and Exhibit F in appropriate order as follows: Exhibit A.2: Supplemental Beneficial Ownership Information Exhibit D.2: Joint Filing Agreement, dated as of February 27, 2026. Exhibit E: *Secured Margin Line of Credit Note, dated as of February 25, 2026. Exhibit F: *Margin Line of Credit Collateral Agreement, dated as of February 25, 2026. *Portions of this exhibit have been redacted in compliance with Regulation S-K Item 601(b)(10). The omitted information is not material and would likely cause competitive harm to the Reporting Persons if publicly disclosed.