Michael A. Carusi - Aug 1, 2025 Form 4 Insider Report for SHOULDER INNOVATIONS, INC. (SI)

Role: Director
Signature: Jeffrey Points, as Attorney-in-Fact
Stock symbol: SI
Transactions as of: Aug 1, 2025
Transactions value $: $3,999,990
Form type: 4
Date filed: 8/5/2025, 04:05 PM
Previous filing: Jul 30, 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Carusi Michael A	Director	C/O SHOULDER INNOVATIONS, INC., 1535 STEELE AVENUE SW, SUITE B, GRAND RAPIDS	Jeffrey Points, as Attorney-in-Fact	2025-08-05	0001306506

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	SI	Common Stock	Conversion of derivative security		+1.62M			1.62M	Aug 1, 2025	See Footnotes	F1, F2, F3
transaction	SI	Common Stock	Purchase	$4M	+267K	+16.48%	$15.00	1.89M	Aug 1, 2025	See Footnotes	F2, F3
transaction	SI	Common Stock	Award	$0	+7.67K		$0.00	7.67K	Aug 1, 2025	Direct	F4

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SI	Series C Convertible Preferred Stock	Conversion of derivative security		-20.9M	-100%		0	Aug 1, 2025	Common Stock	1.1M		See Footnotes	F1, F2, F5
transaction	SI	Series D Convertible Preferred Stock	Conversion of derivative security		-9.95M	-100%		0	Aug 1, 2025	Common Stock	521K		See Footnotes	F1, F2, F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Immediately prior to the closing of the Issuer's initial public offering, the shares of preferred stock of the Issuer automatically converted into shares of Common Stock on a one-for-0.052410901 basis.
F2	LSV Associates II, LLC is the general partner of Lightstone Ventures II, L.P. ("LSV II") and Lightstone Ventures II (A), L.P. ("LSV II (A)") and has sole voting and dispositive power with respect to the shares held by LSV II and LSV II (A). The reporting person is a managing director of LSV Associates II, LLC, and shares voting and dispositive power with respect to the shares held of record by LSV II and LSV II (A). The reporting person disclaims beneficial ownership of such holdings, except to the extent of his pecuniary interest in the shares.
F3	Following the transactions reported in this Form 4, (i) 1,781,479 shares of Common Stock are held by LSV II and (ii) 103,657 shares of Common Stock are held by LSV II (A).
F4	Represents an award of restricted stock units ("RSUs"). The RSUs will vest on the earlier of the date of the annual meeting of stockholders to be held in 2026 or August 1, 2026. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock and has no expiration date.
F5	Consists of (i) 1,036,638 shares of Common Stock underlying Series C Preferred Stock and 492,833 shares of Common Stock underlying Series D Preferred Stock held by LSV II; and (ii) 60,333 shares of Common Stock underlying Series C Preferred Stock and 28,666 shares of Common Stock underlying Series D Preferred Stock held by LSV II (A).