Holder evidence
50
SEC ownership of RHYTHM PHARMACEUTICALS, INC.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001649904.
Lead holder
RA CAPITAL MANAGEMENT, L.P.
13D/G signal
RA CAPITAL MANAGEMENT, L.P.
Latest evidence
31 Mar 2026
- CIK
- 0001649904
- Symbol
- RYTM on Nasdaq
- Location
- Boston, MA
- SEC evidence mix
- 13D/G and 13F
- Lead holder
- RA CAPITAL MANAGEMENT, L.P.
- Latest large-stake holder
- RA CAPITAL MANAGEMENT, L.P.
- Latest evidence date
- 31 Mar 2026
Issuer identity
Ownership snapshot
Ownership snapshot
Top shareholders of RHYTHM PHARMACEUTICALS, INC. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Lead holder
RA CAPITAL MANAGEMENT, L.P.
13D/G signal
RA CAPITAL MANAGEMENT, L.P.
Evidence rows
50
Latest as of
31 Mar 2026
13D/G
13F
Lead comparable stake: 9.9%
13D/G row: RA CAPITAL MANAGEMENT, L.P.
Showing 1-8 of 50 holder rows.
Rank 1 holder
RA CAPITAL MANAGEMENT, L.P.
13D/G
13F
- Ownership
- 9.9%
- Position
- $662.82M
Rank 2 holder
BAKER BROS. ADVISORS LP
13F
13D/G
- Ownership
- 8.9%
- Position
- $487.42M
Rank 3 holder
BlackRock, Inc.
13F
13D/G
- Ownership
- 6.9%
- Position
- $542.45M
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. |
13D/G
13F
Company
|
9.9%
|
$662,816,935
6,666,837 shares
|
+$109,906,623 | 31 Dec 2025 |
| BAKER BROS. ADVISORS LP |
13F
13D/G
Company
|
8.9%
from 13D/G
|
$487,421,887
5,604,483 shares
|
— | 31 Mar 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
6.9%
from 13D/G
|
$542,445,023
6,237,151 shares
|
— | 31 Mar 2026 |
| PRIMECAP MANAGEMENT CO/CA/ |
13D/G
13F
Company
|
5.2%
|
$345,849,272
3,478,669 shares
|
-$77,964,170 | 31 Dec 2025 |
| PERCEPTIVE ADVISORS LLC |
13D/G
13F
Company
|
5.1%
|
$303,708,528
3,519,626 shares
|
-$77,990,196 | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
5%
|
$298,563,575
3,432,949 shares
|
$0 | 31 Mar 2026 |
| GOLDMAN SACHS GROUP INC |
13F
13D/G
Company · THE GOLDMAN SACHS GROUP, INC.
|
3%
from 13D/G
|
$170,933,621
1,965,432 shares
|
— | 31 Mar 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13F
Company
|
4.4%
|
$264,451,244
3,040,718 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$28,049,338.
Buys
$0
Insiders: 0
Sells
$28,049,338
Insiders: 7
Net
-$28,049,338
Shares: -333,485
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 333,485
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 10,257 | $0 | $930,921 | -$930,921 |
| 3-6 | 0 | 25,003 | $0 | $2,588,984 | -$2,588,984 |
| 6-9 | 0 | 69,997 | $0 | $7,447,066 | -$7,447,066 |
| 9-12 | 0 | 228,228 | $0 | $17,082,367 | -$17,082,367 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-18 of 18 reporting-owner rows connected to RHYTHM PHARMACEUTICALS, INC.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
18
Lead holder
David P. Meeker
Net 12M change
-$28,049,337
Latest report
18 May 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| David P. Meeker | President and CEO, Director | $29,698,128 | -$2,837,333 | -8.7% | Mixed | 11 Feb 2026 |
| Hunter C. Smith | Chief Financial Officer | $11,535,524 | -$8,311,513 | -42% | Mixed | 18 May 2026 |
| Yann Mazabraud | EVP, Head of International | $7,532,851 | Mixed | 01 Apr 2026 | ||
| Pamela J. Cramer | Chief Human Resources Officer | $3,775,890 | -$4,797,537 | -56% | Mixed | 11 Feb 2026 |
| Jennifer Kayden Lee | EVP, Head of North America | $3,040,334 | Mixed | 11 Feb 2026 | ||
| Joseph Shulman | Chief Technical Officer | $2,775,638 | -$6,229,323 | -69% | Mixed | 11 Feb 2026 |
| Alastair Garfield | Chief Scientific Officer | $2,371,002 | -$85,483 | -3.5% | Mixed | 11 Feb 2026 |
| Mathers Edward T. | Director | $2,198,720 | Mixed | 12 Mar 2026 | ||
| Linda Shapiro Manning | Chief Medical Officer | $563,250 | Mixed | 09 Feb 2022 | ||
| Lynn A. Tetrault | Director | $421,260 | Mixed | 24 Jun 2025 | ||
| Camille L. Bedrosian | Director | $421,260 | Mixed | 24 Jun 2025 | ||
| Stuart A. Arbuckle | Director | $421,260 | Mixed | 24 Jun 2025 | ||
| David W. J. Mcgirr | Director | $421,260 | -$4,267,494 | -91% | Mixed | 24 Jun 2025 |
| Jennifer L. Good | Director | $421,260 | Mixed | 24 Jun 2025 | ||
| Christophe Jean | Director | $421,260 | Mixed | 24 Jun 2025 | ||
| William T. Roberts | Chief Accounting Officer | $279,459 | Mixed | 29 Mar 2023 | ||
| Christopher Paul German | Corporate Controller & CAO | $120,201 | -$1,520,654 | -93% | Mixed | 15 May 2026 |
| Kimberly J. Popovits | Director | Mixed | 01 Apr 2026 |
Recent insider transactions for RHYTHM PHARMACEUTICALS, INC.
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Reported value | Reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Hunter C. Smith | RYTM | Common Stock | Options Exercise | 2.57% | 3,000 | 119,611 | 18 May 2026 | Direct | ||
| Hunter C. Smith | RYTM | Stock Options (Right to Buy) | Options Exercise | -3.66% | -3,000 | 79,000 | 18 May 2026 | Direct | ||
| Christopher Paul German | RYTM | Common Stock | Sale | -100% | $428,131 | $92.21 | -4,643 | 0 | 15 May 2026 | Direct |
| Christopher Paul German | RYTM | Common Stock | Options Exercise | 2210% | 4,442 | 4,643 | 15 May 2026 | Direct | ||
| Christopher Paul German | RYTM | Stock Options (Right to Buy) | Options Exercise | -65.6% | -4,442 | 2,325 | 15 May 2026 | Direct | ||
| Yann Mazabraud | RYTM | Common Stock | Options Exercise | 24.2% | 12,875 | 66,030 | 01 Apr 2026 | Direct | ||
| Yann Mazabraud | RYTM | Restricted Stock Units | Options Exercise | -72% | -12,875 | 5,000 | 01 Apr 2026 | Direct | ||
| Kimberly J. Popovits | RYTM | Stock Options (Right to Buy) | Award | 10,257 | 10,257 | 01 Apr 2026 | Direct | |||
| Kimberly J. Popovits | RYTM | Restricted Stock Units | Award | 6,808 | 6,808 | 01 Apr 2026 | Direct | |||
| Mathers Edward T. | RYTM | Common Stock | Other | 42.1% | 4,199 | 14,168 | 12 Mar 2026 | See Note 2 | ||
| Christopher Paul German | RYTM | Common Stock | Sale | -97.2% | $502,790 | $89.56 | -5,614 | 160 | 04 Mar 2026 | Direct |
| Christopher Paul German | RYTM | Common Stock | Options Exercise | 35.3% | 1,500 | 5,753 | 04 Mar 2026 | Direct | ||
| Christopher Paul German | RYTM | Stock Options (Right to Buy) | Options Exercise | -28.7% | -1,500 | 3,731 | 04 Mar 2026 | Direct | ||
| Yann Mazabraud | RYTM | Stock Options (Right to Buy) | Award | 35,000 | 35,000 | 02 Mar 2026 | Direct | |||
| Mathers Edward T. | RYTM | Common Stock | Other | 72.7% | 4,198 | 9,969 | 02 Mar 2026 | See Note 2 | ||
| Hunter C. Smith | RYTM | Common Stock | Options Exercise | 5.52% | 6,099 | 116,611 | 02 Mar 2026 | Direct | ||
| Hunter C. Smith | RYTM | Stock Options (Right to Buy) | Options Exercise | -6.26% | -6,099 | 91,401 | 02 Mar 2026 | Direct | ||
| Christopher Paul German | RYTM | Common Stock | Tax liability | -7.44% | -342 | 4,253 | 01 Mar 2026 | Direct | ||
| Christopher Paul German | RYTM | Common Stock | Options Exercise | 33.8% | 1,162 | 4,595 | 01 Mar 2026 | Direct | ||
| Christopher Paul German | RYTM | Restricted Stock Units | Options Exercise | -50% | -1,162 | 1,162 | 01 Mar 2026 | Direct | ||
| Hunter C. Smith | RYTM | Common Stock | Sale | -3.82% | $444,004 | $101.26 | -4,385 | 110,512 | 19 Feb 2026 | Direct |
| Hunter C. Smith | RYTM | Common Stock | Sale | -3.01% | $361,810 | $101.38 | -3,569 | 114,897 | 17 Feb 2026 | Direct |
| Yann Mazabraud | RYTM | Common Stock | Options Exercise | 23.2% | 10,000 | 53,155 | 14 Feb 2026 | Direct | ||
| Yann Mazabraud | RYTM | Restricted Stock Units | Options Exercise | -25% | -10,000 | 30,000 | 14 Feb 2026 | Direct | ||
| Hunter C. Smith | RYTM | Common Stock | Sale | -1.33% | $156,380 | $98.23 | -1,592 | 118,466 | 12 Feb 2026 | Direct |
| Joseph Shulman | RYTM | Stock Options (Right to Buy) | Award | 22,500 | 22,500 | 11 Feb 2026 | Direct | |||
| Joseph Shulman | RYTM | Restricted Stock Units | Award | 15,000 | 15,000 | 11 Feb 2026 | Direct | |||
| David P. Meeker | RYTM | Stock Options (Right to Buy) | Award | 107,850 | 107,850 | 11 Feb 2026 | Direct | |||
| David P. Meeker | RYTM | Restricted Stock Units | Award | 71,900 | 71,900 | 11 Feb 2026 | Direct | |||
| Yann Mazabraud | RYTM | Restricted Stock Units | Award | 23,350 | 23,350 | 11 Feb 2026 | Direct | |||
| Jennifer Kayden Lee | RYTM | Stock Options (Right to Buy) | Award | 32,500 | 32,500 | 11 Feb 2026 | Direct | |||
| Jennifer Kayden Lee | RYTM | Restricted Stock Units | Award | 21,650 | 21,650 | 11 Feb 2026 | Direct | |||
| Christopher Paul German | RYTM | Restricted Stock Units | Award | 5,215 | 5,215 | 11 Feb 2026 | Direct | |||
| Alastair Garfield | RYTM | Stock Options (Right to Buy) | Award | 25,000 | 25,000 | 11 Feb 2026 | Direct | |||
| Alastair Garfield | RYTM | Restricted Stock Units | Award | 16,650 | 16,650 | 11 Feb 2026 | Direct | |||
| Pamela J. Cramer | RYTM | Stock Options (Right to Buy) | Award | 17,500 | 17,500 | 11 Feb 2026 | Direct | |||
| Pamela J. Cramer | RYTM | Restricted Stock Units | Award | 11,650 | 11,650 | 11 Feb 2026 | Direct | |||
| Hunter C. Smith | RYTM | Common Stock | Sale | -2.25% | $272,766 | $98.61 | -2,766 | 120,058 | 11 Feb 2026 | Direct |
| Hunter C. Smith | RYTM | Stock Options (Right to Buy) | Award | 37,500 | 37,500 | 11 Feb 2026 | Direct | |||
| Hunter C. Smith | RYTM | Restricted Stock Units | Award | 25,000 | 25,000 | 11 Feb 2026 | Direct | |||
| Hunter C. Smith | RYTM | Common Stock | Sale | -2.16% | $279,429 | $103.00 | -2,713 | 122,824 | 10 Feb 2026 | Direct |
| Hunter C. Smith | RYTM | Common Stock | Sale | -2.62% | $358,599 | $106.06 | -3,381 | 125,537 | 05 Feb 2026 | Direct |
| Hunter C. Smith | RYTM | Common Stock | Sale | -2.46% | $344,145 | $105.99 | -3,247 | 128,918 | 04 Feb 2026 | Direct |
| Yann Mazabraud | RYTM | Common Stock | Options Exercise | 14.6% | 5,500 | 43,155 | 01 Feb 2026 | Direct | ||
| Yann Mazabraud | RYTM | Restricted Stock Units | Options Exercise | -33.3% | -5,500 | 11,000 | 01 Feb 2026 | Direct | ||
| Joseph Shulman | RYTM | Common Stock | Tax liability | -25.5% | -6,507 | 18,970 | 01 Feb 2026 | Direct | ||
| Joseph Shulman | RYTM | Common Stock | Options Exercise | 199.4% | 16,968 | 25,477 | 01 Feb 2026 | Direct | ||
| Joseph Shulman | RYTM | Restricted Stock Units | Options Exercise | -100% | -16,968 | 0 | 01 Feb 2026 | Direct | ||
| Jennifer Kayden Lee | RYTM | Common Stock | Tax liability | -32.4% | -9,237 | 19,233 | 01 Feb 2026 | Direct | ||
| Jennifer Kayden Lee | RYTM | Common Stock | Options Exercise | 386% | 22,612 | 28,470 | 01 Feb 2026 | Direct |
* indicates a reported price that failed the local validity check.