Sphere Entertainment (SPHR) COO nets RSUs and uses 8,808 shares for taxes

Rhea-AI Filing Summary

Sphere Entertainment Co. President & COO Jennifer Koester had 17,254 restricted stock units convert into the same number of Class A Common shares on March 13, 2026, as part of a March 12, 2025 grant under the 2020 Employee Stock Plan. These RSUs are scheduled to vest in three equal annual installments through March 15, 2028.

To cover tax withholding obligations on this vesting, 8,808 Class A shares were withheld at $105.70 per share rather than sold in the open market. After these transactions, Koester directly holds 30,918 shares of Class A Common Stock.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Koester Jennifer

(Last) (First) (Middle)

TWO PENNSYLVANIA PLAZA

(Street)

NEW YORK NY 10121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Sphere Entertainment Co. [ SPHR ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President & COO, Sphere

3. Date of Earliest Transaction (Month/Day/Year)
03/13/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	03/13/2026		M		17,254	A	$0.00(1)	39,726	D
Class A Common Stock	03/13/2026		F(2)		8,808	D	$105.7	30,918	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(1)	03/13/2026		M			17,254	(1)	03/15/2028	Class A Common Stock	17,254	$0	34,509	D

Explanation of Responses:

1. Each restricted stock unit ("RSU") was granted on March 12, 2025 under the Sphere Entertainment Co. ("SPHR") 2020 Employee Stock Plan, as amended and represents a right to receive one share of Class A Common Stock or the cash equivalent thereof. One-third of the RSUs vested and were settled on March 13, 2026. One-third of the RSUs are scheduled to vest and settle on March 15, 2027. The remaining one-third of the RSUs are scheduled to vest and settle on March 15, 2028.

2. Represents RSUs of SPHR withheld to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs described in footnote 1, exempt under Rule 16b-3.

	/s/ Mark C. Cresitello, Attorney-in-Fact for Jennifer Koester	03/17/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What did Sphere Entertainment (SPHR) executive Jennifer Koester report in this Form 4?

Jennifer Koester reported RSU vesting and related tax withholding. 17,254 restricted stock units converted into Class A shares, and 8,808 of those shares were withheld to satisfy tax obligations. These are compensation-related events, not open‑market stock purchases or sales.

How many Sphere Entertainment (SPHR) shares did Jennifer Koester acquire through RSU vesting?

Koester acquired 17,254 Class A shares via RSU settlement. The RSUs were granted March 12, 2025 under the 2020 Employee Stock Plan, with one‑third vesting and settling on March 13, 2026, and additional thirds scheduled in 2027 and 2028.

How many Sphere Entertainment (SPHR) shares were used to cover Jennifer Koester’s taxes?

8,808 Class A shares were withheld for tax obligations. These shares were valued at $105.70 per share and were delivered to satisfy tax withholding related to the March 13, 2026 RSU vesting, rather than being sold in the open market.

What is Jennifer Koester’s Sphere Entertainment (SPHR) share ownership after this Form 4?

Koester directly holds 30,918 Class A shares after the transactions. This figure reflects the 17,254 shares received from RSU vesting on March 13, 2026, net of the 8,808 shares withheld to cover tax liabilities associated with that vesting event.

What is the vesting schedule of Jennifer Koester’s Sphere Entertainment (SPHR) RSUs?

The RSUs vest in three equal annual installments. One‑third vested and settled on March 13, 2026, with additional one‑third portions scheduled to vest and settle on March 15, 2027, and March 15, 2028, under the 2020 Employee Stock Plan.

Were Jennifer Koester’s Sphere Entertainment (SPHR) transactions open-market trades?

No, the transactions were compensation and tax-related. Shares were acquired through the conversion of restricted stock units and a portion was withheld to satisfy tax obligations, so there were no open‑market purchases or discretionary stock sales reported here.