Rhythm Pharmaceuticals Inc
Ownership
Ownership Structure
Who owns Rhythm Pharmaceuticals Inc (RYTM)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 81.4% of the shares are freely tradable; institutional investors hold 110.0%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| RA Capital Management, LLC | 9.68 | 6,666,837 | +0.0 | 03/31/2026 |
| BlackRock Inc | 9.06 | 6,237,151 | -1.0 | 03/31/2026 |
| Baker Bros Advisors LP | 8.14 | 5,604,483 | +0.0 | 03/31/2026 |
| PRIMECAP Management Company | 4.60 | 3,168,853 | -7.3 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 4.42 | 3,040,718 | +0.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 4.31 | 2,967,825 | +0.0 | 03/31/2026 |
| Perceptive Advisors LLC | 3.76 | 2,586,295 | +9.0 | 06/30/2026 |
| State Street Corp | 3.30 | 2,271,851 | +3.3 | 03/31/2026 |
| Westfield Capital Management Company, L.P. | 3.21 | 2,208,595 | +14.5 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 3.17 | 2,184,847 | +0.3 | 07/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Meeker David P | President and CEO | 239,258 | 23,375,507 $ | Sep 14, 2026 | direct |
| Smith Hunter C | Chief Financial Officer | 114,024 | 11,140,145 $ | Aug 31, 2026 | direct |
| Mazabraud Yann | EVP, Head of International | 55,655 | 5,437,494 $ | Aug 12, 2026 | direct |
| Shulman Joseph | Chief Technical Officer | 15,915 | 1,554,896 $ | Aug 13, 2026 | direct |
| Garfield Alastair | Chief Scientific Officer | 2,295 | 224,222 $ | Aug 13, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sep 14, 2026 | Meeker David P | President and CEO | Sell | 2,300 | 105.19 | 241,937 |
| Sep 14, 2026 | Meeker David P | President and CEO | Sell | 1,817 | 104.55 | 189,965 |
| Sep 14, 2026 | Meeker David P | President and CEO | Sell | 8,698 | 103.43 | 899,634 |
| Sep 14, 2026 | Meeker David P | President and CEO | Sell | 30,746 | 102.35 | 3,146,761 |
| Sep 14, 2026 | Meeker David P | President and CEO | Sell | 6,439 | 101.75 | 655,145 |
| Sep 14, 2026 | Meeker David P | President and CEO | Other | 50,000 | 6.05 | 302,500 |
| Aug 31, 2026 | Smith Hunter C | Chief Financial Officer | Sell | 28,188 | 106.20 | 2,993,647 |
| Aug 31, 2026 | Smith Hunter C | Chief Financial Officer | Sell | 11,514 | 105.37 | 1,213,232 |
| Aug 31, 2026 | Smith Hunter C | Chief Financial Officer | Sell | 23,072 | 104.59 | 2,413,034 |
| Aug 31, 2026 | Smith Hunter C | Chief Financial Officer | Other | 57,187 | 25.79 | 1,474,853 |
| Aug 13, 2026 | Shulman Joseph | Chief Technical Officer | Sell | 5,079 | 119.75 | 608,210 |
| Aug 13, 2026 | Shulman Joseph | Chief Technical Officer | Other | 2,024 | 6.80 | 13,763 |
| Aug 13, 2026 | Garfield Alastair | Chief Scientific Officer | Sell | 800 | 119.17 | 95,335 |
| Aug 13, 2026 | Garfield Alastair | Chief Scientific Officer | Sell | 3,400 | 118.28 | 402,167 |
| Aug 13, 2026 | Garfield Alastair | Chief Scientific Officer | Sell | 1,556 | 117.08 | 182,170 |
| Aug 13, 2026 | Garfield Alastair | Chief Scientific Officer | Sell | 2,007 | 116.11 | 233,031 |
| Aug 13, 2026 | Lee Jennifer Kayden | EVP, Head of North America | Sell | 75,834 | 117.38 | 8,901,531 |
| Aug 13, 2026 | Lee Jennifer Kayden | EVP, Head of North America | Other | 21,601 | 6.80 | 146,887 |
| Aug 13, 2026 | Lee Jennifer Kayden | EVP, Head of North America | Other | 35,000 | 24.29 | 850,150 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Sell | 17,319 | 117.47 | 2,034,439 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Sell | 18,208 | 116.49 | 2,121,125 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Sell | 14,568 | 115.43 | 1,681,541 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Sell | 3,605 | 114.70 | 413,477 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Sell | 1,000 | 112.86 | 112,856 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Sell | 2,300 | 111.80 | 257,138 |
| Aug 12, 2026 | Mazabraud Yann | EVP, Head of International | Other | 46,625 | 6.80 | 317,050 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 18, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.