[Form 4] Rhythm Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Form 4 highlights for Rhythm Pharmaceuticals, Inc. (RYTM)

• Reporting insider: Chief Financial Officer Hunter C. Smith
• Transaction date: 07/09/2025 (filed 07/11/2025)
• Option exercise: 42,120 stock options exercised at an exercise price of $6.88.
• Share sales: The same 42,120 shares were immediately disposed of in three open-market sales:
  • 17,113 shares at a weighted average price of $75.3842
  • 1,607 shares at a weighted average price of $76.1707
  • 23,400 shares at a price of $84.50
• Proceeds (approx.): About $3.2 million based on the weighted average sale prices disclosed.
• Remaining holdings: 116,915 shares of common stock held directly after the transactions, plus 28,088 fully vested options that remain outstanding.
• 10b5-1 plan: Sales were executed under a Rule 10b5-1 trading plan adopted on 02/28/2025.

The filing indicates a net reduction of roughly 26% in the CFO’s direct common-stock position (from 159,035 to 116,915 shares). No information about company fundamentals or operational performance is included; the document is limited to insider trading activity.

Positive

• None.

Negative

• CFO insider selling: Hunter C. Smith disposed of 42,120 shares, reducing his direct holding by approximately 26%.

Insights

Financial Analyst

TL;DR CFO sold 42k shares after exercising options; transaction is modest and pre-planned, suggesting limited direct impact on valuation.

The exercise-and-sale pattern shows classic cashless exercise: Hunter Smith used option gains to monetize shares without increasing net share count. Although insider selling can be perceived negatively, the sale appears routine—conducted under a 10b5-1 plan and leaving the executive with a sizeable 116,915-share stake and 28,088 remaining options. The dollar value (~$3.2 M) is not material relative to Rhythm’s >$2 B market cap (based on recent prices). As such, I view market impact as neutral; no operational signals are presented.

Corporate Governance Specialist

TL;DR Pre-planned 10b5-1 sales mitigate governance concerns; insider still retains meaningful equity.

From a governance lens, two elements stand out: (1) adherence to a 10b5-1 plan, which curbs information-asymmetry risk; and (2) retention of over 116k shares post-sale, aligning the CFO’s interests with shareholders. The 26% stake reduction is notable but not alarming given the remaining exposure and full vesting of options. Overall, I classify the disclosure as low-impact with neutral governance implications.

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).

X

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^*

Smith Hunter C

(Last) (First) (Middle)

C/O RHYTHM PHARMACEUTICALS, INC.

222 BERKELEY STREET, 12TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
RHYTHM PHARMACEUTICALS, INC. [ RYTM ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
07/09/2025

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	07/09/2025		M		42,120	A	$6.88	159,035	D
Common Stock	07/09/2025		S(1)		17,113	D	$75.3842(2)	141,922	D
Common Stock	07/09/2025		S(1)		1,607	D	$76.1707(3)	140,315	D
Common Stock	07/09/2025		S(1)		23,400	D	$84.5	116,915	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
Stock Options (Right to Buy)	$6.88	07/09/2025		M			42,120	(4)	08/08/2027	Common Stock	42,120	$0	28,088	D

Explanation of Responses:

1. The sale reported in the Form 4 was effected pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on February 28, 2025.

2. The price reported in Column 4 is a weighted average price. The securities were sold in multiple transactions at prices ranging from $75.01 to $75.70 per common stock. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

3. The price reported in Column 4 is a weighted average price. The securities were sold in multiple transactions at prices ranging from $76.17 to $76.18 per common stock. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

4. The stock option is fully vested.

	/s/ Stephen Vander Stoep, attorney-in-fact for Hunter C. Smith	07/11/2025
	** 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.
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FAQ

How many Rhythm Pharmaceuticals (RYTM) shares did the CFO sell?

He sold 42,120 shares of common stock on 07/09/2025.

What prices were the RYTM shares sold at?

Sales occurred at weighted average prices of $75.3842, $76.1707, and $84.50.

What was the exercise price of the options exercised by the CFO?

The options were exercised at $6.88 per share.

How many RYTM shares does the CFO still own after the transaction?

He retains 116,915 shares directly plus 28,088 fully vested options.

Was the sale executed under a 10b5-1 trading plan?

Yes. The filing states the sales were made pursuant to a Rule 10b5-1 plan adopted on 02/28/2025.