Latest Period
Q1 2026
Security Snapshot
RHYTHM PHARMACEUTICALS, INC. - Common Stock, $0.001 par value per share (RYTM) Institutional Ownership
CUSIP: 76243J105
13F Institutional Holders and Ownership History from Q4 2017 to Q1 2026
Institutions Reporting
283
Shares (Excl. Options)
73,450,337
Price
$86.97
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- Security type / class
- Equity / Common Stock, $0.001 par value per share
- Symbol
- RYTM on Nasdaq
- Shares outstanding
- 69,012,275
- Reported price per share
- $93.72
- Price from insider filings
- $93.72
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 73,450,337
- Total reported value
- $6,388,306,391
- Portfolio coverage rank
- 0.01%
- Share change
- +520,140
- Value change
- -$49,270,895
- Number of holders
- 283
Security identity
Issuer context
Latest holder snapshot
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors
Key facts
- RYTM - RHYTHM PHARMACEUTICALS, INC. - Common Stock, $0.001 par value per share is tracked under CUSIP 76243J105.
- 283 institutions reported positions in Q1 2026.
- 7 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 278 to 283 between Q4 2025 and Q1 2026.
- Reported value moved from $7,800,497,062 to $6,388,306,391.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC Evidence
Latest holder context comes from 283 institutions filings for Q1 2026.
Security key
76243J105
Latest holder period
Q1 2026
13F holders
283
13D/G owners
7
CIK / CUSIP context first
Open Q1 2026 holders
RYTM full holder history
RHYTHM PHARMACEUTICALS, INC. SEC filings
RHYTHM PHARMACEUTICALS, INC. company facts
RHYTHM PHARMACEUTICALS, INC. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 76243J105:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
7
Security
RYTM
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 9.9% | +13% | $662,816,935 | +$109,906,623 | 6,666,837 | +20% | RA Capital Management, L.P. | 31 Dec 2025 |
| BAKER BROS. ADVISORS LP | 8.9% | $360,984,750 | 5,604,483 | Baker Bros. Advisors LP | 31 Mar 2025 | |||
| BlackRock, Inc. | 6.9% | $281,130,327 | 4,364,700 | BlackRock, Inc. | 31 Mar 2025 | |||
| PERCEPTIVE ADVISORS LLC | 5.1% | -24% | $303,708,528 | -$77,990,196 | 3,519,626 | -20% | Perceptive Advisors LLC | 31 Mar 2026 |
| PRIMECAP MANAGEMENT CO/CA/ | 5.2% | -20% | $345,849,272 | -$77,964,170 | 3,478,669 | -18% | PRIMECAP MANAGEMENT CO/CA/ | 31 Dec 2025 |
| VANGUARD CAPITAL MANAGEMENT LLC | 5% | $298,563,575 | 3,432,949 | Vanguard Capital Management | 31 Mar 2026 | |||
| GOLDMAN SACHS GROUP INC | 3% | $117,157,406 | 1,818,932 | THE GOLDMAN SACHS GROUP, INC. | 31 Dec 2024 |
As of 31 Mar 2026, 283 institutional investors reported holding 73,450,337 shares of RHYTHM PHARMACEUTICALS, INC. - Common Stock, $0.001 par value per share (RYTM). This represents 106% of the company’s total 69,012,275 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
79%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 9.7% | 6,666,837 | 0% | 6.1% | $579,814,814 |
| BlackRock, Inc. | 9% | 6,237,151 | -0.96% | 0.01% | $542,445,023 |
| BAKER BROS. ADVISORS LP | 8.1% | 5,604,483 | 0% | 2.8% | $487,421,887 |
| PRIMECAP MANAGEMENT CO/CA/ | 5% | 3,417,509 | -1.8% | 0.23% | $297,220,757 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 4.4% | 3,040,718 | 0% | 0.01% | $264,451,244 |
| VANGUARD CAPITAL MANAGEMENT LLC | 4.3% | 2,967,825 | 0% | 0.01% | $258,111,740 |
| PERCEPTIVE ADVISORS LLC | 3.4% | 2,373,795 | -6.8% | 4.1% | $206,448,951 |
| STATE STREET CORP | 3.3% | 2,271,851 | +3.3% | 0.01% | $197,582,881 |
| GOLDMAN SACHS GROUP INC | 2.8% | 1,965,432 | +7.3% | 0.02% | $170,933,621 |
| WESTFIELD CAPITAL MANAGEMENT CO LP | 2.8% | 1,929,123 | +52% | 0.7% | $167,775,827 |
| FMR LLC | 2.4% | 1,689,671 | -0.98% | 0.01% | $146,950,721 |
| PRICE T ROWE ASSOCIATES INC /MD/ | 2.4% | 1,654,876 | +6% | 0.02% | $143,925,000 |
| Polar Capital Holdings Plc | 2.3% | 1,615,586 | +36% | 0.61% | $140,507,514 |
| JPMORGAN CHASE & CO | 2.3% | 1,553,644 | +9.1% | 0.01% | $120,019,069 |
| CITADEL ADVISORS LLC | 2.1% | 1,418,619 | +825% | 0.09% | $123,377,295 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.1% | 1,416,269 | +2.9% | 0.01% | $123,197,314 |
| FEDERATED HERMES, INC. | 1.9% | 1,286,303 | -21% | 0.18% | $111,869,772 |
| Checkpoint Capital L.P. | 1.8% | 1,227,200 | +24% | 38% | $106,729,584 |
| Capital Research Global Investors | 1.6% | 1,115,460 | +13% | 0.02% | $97,011,556 |
| JANUS HENDERSON GROUP PLC | 1.3% | 918,153 | -18% | 0.04% | $79,886,248 |
| ALLIANCEBERNSTEIN L.P. | 1.3% | 910,413 | -2.1% | 0.03% | $97,450,608 |
| Point72 Asset Management, L.P. | 1.2% | 846,801 | +97% | 0.13% | $73,646,283 |
| Woodline Partners LP | 1.1% | 758,891 | +10% | 0.25% | $66,000,750 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 1.1% | 725,744 | +17% | 0.1% | $63,117,956 |
| Siren, L.L.C. | 1.1% | 725,511 | +45% | 1.7% | $63,097,692 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
34
Latest
Q1 2026
Rows shown
1-25 of 34
| Period | Reported Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 73,450,337 | $6,388,306,391 | -$49,270,895 | $86.97 | 283 |
| 2025 Q4 | 72,869,648 | $7,800,497,062 | +$220,704,819 | $107.04 | 278 |
| 2025 Q3 | 70,886,984 | $7,158,776,142 | +$449,472,938 | $100.99 | 263 |
| 2025 Q2 | 66,543,505 | $4,204,958,379 | +$136,584,141 | $63.19 | 225 |
| 2025 Q1 | 64,595,384 | $3,424,910,613 | -$18,829,096 | $52.97 | 226 |
| 2024 Q4 | 64,917,500 | $3,634,217,578 | -$158,677,402 | $55.98 | 202 |
| 2024 Q3 | 67,700,036 | $3,546,202,706 | -$85,917,668 | $52.39 | 175 |
| 2024 Q2 | 69,300,680 | $2,846,175,742 | +$52,795,226 | $41.06 | 164 |
| 2024 Q1 | 68,030,458 | $2,946,208,413 | +$55,358,404 | $43.33 | 166 |
| 2023 Q4 | 66,696,112 | $3,065,811,725 | -$41,849,707 | $45.97 | 167 |
| 2023 Q3 | 68,143,293 | $1,562,080,292 | +$58,456,223 | $22.92 | 143 |
| 2023 Q2 | 66,212,640 | $1,092,127,229 | +$94,106,398 | $16.49 | 116 |
| 2023 Q1 | 60,335,883 | $1,076,382,910 | -$49,077,961 | $17.84 | 125 |
| 2022 Q4 | 62,378,764 | $1,816,485,551 | +$85,568,575 | $29.12 | 116 |
| 2022 Q3 | 59,549,165 | $1,446,896,472 | +$426,232,319 | $24.50 | 99 |
| 2022 Q2 | 45,934,145 | $190,627,988 | -$18,795,957 | $4.15 | 82 |
| 2022 Q1 | 48,841,709 | $562,605,977 | +$4,688,818 | $11.52 | 105 |
| 2021 Q4 | 48,449,400 | $483,522,595 | -$537,879 | $9.98 | 94 |
| 2021 Q3 | 47,950,622 | $626,233,206 | +$2,428,146 | $13.06 | 93 |
| 2021 Q2 | 42,614,232 | $834,516,313 | -$3,429,160 | $19.58 | 101 |
| 2021 Q1 | 47,577,014 | $1,011,965,096 | +$147,271,703 | $21.27 | 119 |
| 2020 Q4 | 40,510,233 | $1,201,291,923 | +$39,479,834 | $29.73 | 114 |
| 2020 Q3 | 39,249,591 | $850,611,960 | -$43,710,727 | $21.67 | 114 |
| 2020 Q2 | 41,237,373 | $919,577,883 | +$11,957,883 | $22.30 | 89 |
| 2020 Q1 | 40,805,984 | $621,064,603 | -$34,159,931 | $15.22 | 80 |