[Form 4] LB PHARMACEUTICALS INC Insider Trading Activity

Rhea-AI Filing Summary

Deep Track reporting persons disclosed multiple transactions in LB PHARMACEUTICALS INC (LBRX) dated 09/12/2025. Series C preferred shares converted immediately prior to the issuer's IPO, producing common stock on a conversion ratio tied to the IPO price. Deep Track Biotechnology Master Fund, Ltd. reported receipt of 686,138 common shares from conversion. The reporting persons also acquired 2,000,000 common shares and 666,666 common shares by purchase at $15.00 per share. After these transactions, Deep Track Biotechnology Master Fund, Ltd. beneficially owned 2,686,138 shares directly and Deep Track Special Opportunities Fund, LP held 666,666 shares indirectly.

Positive

• Acquisition of large share blocks: purchases of 2,000,000 and 666,666 common shares at $15.00 each
• Conversion to common stock: Series C preferred converted resulting in 686,138 common shares
• Clear disclosure of relationships: filers provide managerial links and disclaimers for indirect ownership

Negative

• No negative items explicitly disclosed

Insights

Securities/Financial Analyst

TL;DR: Significant insider purchases and conversion increased Deep Track entities' common shareholdings ahead of or concurrent with the issuer's IPO.

The Form 4 shows a mix of conversion and open-market purchases on 09/12/2025: a conversion of Series C preferred into 686,138 common shares and purchases totaling 2,666,666 common shares at $15.00 each. These transactions raise the reporting persons' direct beneficial ownership to 2,686,138 shares and add an indirect holding of 666,666 shares via Deep Track Special Opportunities Fund, LP. From a capital-structure perspective, the conversion of Series C preferred increased common float by the converted amount; purchase prices are explicitly disclosed as $15.00 per share.

Corporate Governance Expert

TL;DR: Reporting structure and disclaimers clarify indirect ownership and managerial relationships without admitting broader beneficial ownership.

Filers disclose typical managerial relationships: Deep Track Capital, LP is the investment manager of the funds and David Kroin is the managing member of the general partner. The filing includes standard disclaimers that Deep Track Capital, LP and Mr. Kroin disclaim beneficial ownership except to their pecuniary interests. The Form 4 is signed by the relevant parties on 09/16/2025, and the Explanation clarifies that conversions occurred immediately prior to the issuer's IPO closing.

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

1. Name and Address of Reporting Person^*

Deep Track Biotechnology Master Fund, Ltd.

(Last) (First) (Middle)

C/O WALKERS CORPORATE LIMITED

190 ELGIN AVE

(Street)

GEORGE TOWN E9 KY1-9001

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
LB PHARMACEUTICALS INC [ LBRX ]

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

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
09/12/2025

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

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

	Form filed by One Reporting Person
X	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	09/12/2025		C		686,138	A	(1)	686,138	D(2)
Common Stock	09/12/2025		P		2,000,000	A	$15	2,686,138	D(2)
Common Stock	09/12/2025		P		666,666	A	$15	666,666	I	By Deep Track Special Opportunities Fund, LP(3)

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
Series C Preferred Stock	(1)	09/12/2025		C			16,666,667	(1)	(1)	Common Stock	686,138	(1)	0	D(2)

1. Name and Address of Reporting Person^*

Deep Track Biotechnology Master Fund, Ltd.

(Last) (First) (Middle)

C/O WALKERS CORPORATE LIMITED

190 ELGIN AVE

(Street)

GEORGE TOWN E9 KY1-9001

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Deep Track Capital, LP

(Last) (First) (Middle)

200 GREENWICH AVE, 3RD FLOOR

(Street)

GREENWICH CT 06830

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

KROIN DAVID

(Last) (First) (Middle)

C/O DEEP TRACK CAPITAL, LP

200 GREENWICH AVE, 3RD FLOOR

(Street)

GREENWICH CT 06830

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Each share of Series C Preferred Stock automatically converted immediately prior to the closing of the Issuer's initial public offering for no additional consideration at a conversion ratio that was dependent upon the initial price per share to the public in the Issuer's initial public offering.

2. Represents securities held by Deep Track Biotechnology Master Fund, Ltd. Deep Track Capital, LP is the investment manager of Deep Track Biotechnology Master Fund, Ltd. Mr. David Kroin is the managing member of Deep Track Capital GP, LLC, the general partner of Deep Track Capital, LP., and by virtue of such status may be deemed to be the beneficial owner of the shares owned by Deep Track Biotechnology Master Fund, Ltd. Deep Track Capital, LP and Mr. Kroin disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests.

3. Represents securities held by Deep Track Special Opportunities Fund, LP. Deep Track Capital, LP is the investment manager of Deep Track Special Opportunities Fund LP. Mr. David Kroin is the managing member of Deep Track Capital GP, LLC, the general partner of Deep Track Capital, LP., and by virtue of such status may be deemed to be the beneficial owner of the shares owned by Deep Track Special Opportunities Fund, LP. Deep Track Capital, LP and Mr. Kroin disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests.

	Deep Track Biotechology Master Fund, Ltd. /s/ David Kroin, Director	09/16/2025
	Deep Track Capital, LP /s/ David Kroin, Managing Member of the General Partner of the Investment Adviser	09/16/2025
	/s/ David Kroin	09/16/2025
	** 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 transactions did Deep Track report for LBRX on 09/12/2025?

The Form 4 reports conversion of Series C preferred into 686,138 common shares and purchases of 2,000,000 and 666,666 common shares at $15.00 per share, all dated 09/12/2025.

How many LBRX shares does Deep Track Biotechnology Master Fund, Ltd. beneficially own after these transactions?

After the reported transactions, Deep Track Biotechnology Master Fund, Ltd. directly beneficially owned 2,686,138 common shares.

Did any Deep Track entity hold shares indirectly and how many?

Yes. Deep Track Special Opportunities Fund, LP is reported as holding 666,666 common shares indirectly.

At what price were the purchased LBRX shares acquired?

The purchases were executed at a price of $15.00 per share.

Who signed the Form 4 filings for these transactions?

The forms were signed by David Kroin on behalf of Deep Track Biotechnology Master Fund, Ltd., Deep Track Capital, LP, and personally, with signature dates of 09/16/2025.