Hunter C. Smith - 31 Aug 2026 Form 4 Insider Report for RHYTHM PHARMACEUTICALS, INC. (RYTM)

Reporting relationship: Chief Financial Officer
Issuer ticker: RYTM
Reported as of: 31 Aug 2026
Net transaction value: -$6,619,913
SEC form: 4
Accepted by SEC: 01 Sep 2026, 16:22:52 UTC
Prior SEC filing: 20 May 2026
Source filing: View source filing
Reporting owner signature: /s/ Stephen Vander Stoep, attorney-in-fact for Hunder Smith

Key filing fact

Hunter C. Smith filed Form 4 for RHYTHM PHARMACEUTICALS, INC. (RYTM) on 01 Sep 2026.

Key facts

This page summarizes Hunter C. Smith's Form 4 filing for RHYTHM PHARMACEUTICALS, INC. (RYTM).
5 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 01 Sep 2026, 16:22.

Change

Previous filing in this sequence was filed on 20 May 2026.
Current net transaction value: -$6,619,913.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001636385 Primary reporting owner

Smith Hunter C

Relationship: Chief Financial Officer
Address: C/O RHYTHM PHARMACEUTICALS, INC., 222 BERKELEY STREET, 12TH FLOOR, BOSTON
Signature: /s/ Stephen Vander Stoep, attorney-in-fact for Hunder Smith
Signature date: 01 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

RYTM transaction

Common Stock

Options Exercise

Transaction value
Shares: +57,187
Change %: +48%
Price: $25.79^*
Shares after: 176,798
Date: 31 Aug 2026
Ownership: Direct
Footnotes: F1

RYTM transaction

Common Stock

Sale

Transaction value: $2,413,034
Shares: -23,072
Change %: -13%
Price: $104.59
Shares after: 153,726
Date: 31 Aug 2026
Ownership: Direct
Footnotes: F1, F2

RYTM transaction

Common Stock

Sale

Transaction value: $1,213,232
Shares: -11,514
Change %: -7.5%
Price: $105.37
Shares after: 142,212
Date: 31 Aug 2026
Ownership: Direct
Footnotes: F1, F3

RYTM transaction

Common Stock

Sale

Transaction value: $2,993,647
Shares: -28,188
Change %: -20%
Price: $106.20
Shares after: 114,024
Date: 31 Aug 2026
Ownership: Direct
Footnotes: F1, F4

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

RYTM transaction Derivative

Employee Stock Option (Right to Buy)

Options Exercise

Transaction value
Shares: -57,187
Change %: -94%
Price: $0.000000^*
Shares after: 3,813
Date: 31 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 57,187
Exercise price: $25.79
Footnotes: F1, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 5 footnotes

Footnote F1

The exercise and sales reported in this form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 13, 2026.

Footnote F2

The price reported in Column 4 is a weighted average price. The securities were sold in multiple transactions at prices ranging from $104.04 to $105.03 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.

Footnote F3

The price reported in Column 4 is a weighted average price. The securities were sold in multiple transactions at prices ranging from $105.04 to $106.01 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.

Footnote F4

The price reported in Column 4 is a weighted average price. The securities were sold in multiple transactions at prices ranging from $106.05 to $106.88 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.

Footnote F5

This option was granted on February 14, 2018 and the shares underlying this option vested in sixteen equal quarterly installments.