Shoulder Innovations (SI) CEO Robert Ball acquires ESPP shares, now holds 120,118

Rhea-AI Filing Summary

Shoulder Innovations, Inc. CEO & Executive Chairman Robert Joseph Ball reported acquiring additional common stock through the company’s 2025 Employee Stock Purchase Plan. On December 31, 2025, he acquired 1,661 shares of common stock at a purchase price of $12.16 per share, which the plan set at 85% of the closing price of the company’s common stock on that date. Following this ESPP purchase, Ball beneficially owned 120,118 shares of Shoulder Innovations common stock held directly.

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^*

Ball Robert Joseph

(Last) (First) (Middle)

C/O SHOULDER INNOVATIONS, INC.

1535 STEELE AVENUE SW, SUITE B

(Street)

GRAND RAPIDS MI 49507

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
SHOULDER INNOVATIONS, INC. [ SI ]

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

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO & Executive Chairman

3. Date of Earliest Transaction (Month/Day/Year)
12/31/2025

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
Common Stock	12/31/2025		A(1)	V	1,661	A	$12.16(2)	120,118	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

Explanation of Responses:

1. The Reporting Person is voluntarily reporting the acquisition of shares under the Issuer's 2025 Employee Stock Purchase Plan ("ESPP") .

2. In accordance with the ESPP, these shares were purchased at a price equal to 85% of the closing price of the Issuer's common stock on December 31, 2025.

Remarks:

	/s/ Jeffrey Points, as Attorney-in-Fact	01/08/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Shoulder Innovations (SI) report in this Form 4?

The filing reports that Robert Joseph Ball, CEO & Executive Chairman of Shoulder Innovations, acquired 1,661 shares of common stock on December 31, 2025 under the company’s 2025 Employee Stock Purchase Plan.

At what price did Robert Joseph Ball acquire Shoulder Innovations (SI) shares?

The 1,661 shares of Shoulder Innovations common stock were purchased at $12.16 per share, which the plan set at 85% of the closing price of the common stock on December 31, 2025.

How many Shoulder Innovations (SI) shares does Robert Joseph Ball own after this transaction?

After the reported acquisition, Robert Joseph Ball beneficially owned 120,118 shares of Shoulder Innovations common stock in total, held directly.

What is the source of the shares acquired by Robert Joseph Ball in this filing?

The shares were acquired through Shoulder Innovations’ 2025 Employee Stock Purchase Plan (ESPP), as the reporting person voluntarily disclosed in the footnotes.

Does the Form 4 indicate whether the ownership is direct or indirect for these Shoulder Innovations (SI) shares?

The filing classifies the ownership of the 120,118 shares as direct (D), with no indirect ownership entity or structure noted in the ownership description.

What role does Robert Joseph Ball hold at Shoulder Innovations (SI)?

Robert Joseph Ball is identified as both a Director and an Officer of Shoulder Innovations, serving as CEO & Executive Chairman.