| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| BAKER BROS. ADVISORS LP | 8.9% | $360,984,750 | 5,604,483 | Baker Bros. Advisors LP | 31 Mar 2025 | |||
| RA CAPITAL MANAGEMENT, L.P. | 8.7% | $482,169,825 | 5,561,359 | RA Capital Management, L.P. | 30 Jun 2025 | |||
| VANGUARD GROUP INC | 7.5% | $504,589,163 | 4,996,427 | The Vanguard Group | 30 Sep 2025 | |||
| PERCEPTIVE ADVISORS LLC | 6.8% | $284,913,835 | 4,423,441 | Perceptive Advisors LLC | 31 Mar 2025 | |||
| BlackRock, Inc. | 6.9% | $281,130,327 | 4,364,700 | BlackRock, Inc. | 31 Mar 2025 | |||
| PRIMECAP MANAGEMENT CO/CA/ | 6.4% | -16% | $430,506,130 | -$62,126,826 | 4,262,859 | -13% | PRIMECAP MANAGEMENT CO/CA/ | 30 Sep 2025 |
| GOLDMAN SACHS GROUP INC | 3% | $117,157,406 | 1,818,932 | THE GOLDMAN SACHS GROUP, INC. | 31 Dec 2024 |
As of 30 Sep 2025, 262 institutional investors reported holding 70,889,646 shares of RHYTHM PHARMACEUTICALS, INC. - COM (RYTM). This represents 107% of the company’s total 66,399,673 outstanding shares.
The largest institutional shareholders of RHYTHM PHARMACEUTICALS, INC. - COM (RYTM) together control 82% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| BlackRock, Inc. | 9.5% | 6,302,215 | +0.55% | 0.01% | $636,460,694 |
| RA CAPITAL MANAGEMENT, L.P. | 8.6% | 5,681,359 | +2.2% | 7.1% | $573,760,445 |
| BAKER BROS. ADVISORS LP | 8.4% | 5,604,483 | 0% | 4.1% | $565,996,738 |
| VANGUARD GROUP INC | 7.5% | 4,996,427 | +39% | 0.01% | $504,589,163 |
| PRIMECAP MANAGEMENT CO/CA/ | 6.4% | 4,262,859 | -13% | 0.33% | $430,506,130 |
| NEA Management Company, LLC | 4.4% | 2,909,956 | 0% | 16% | $293,876,456 |
| PERCEPTIVE ADVISORS LLC | 3.7% | 2,438,969 | +0.85% | 7.2% | $246,311,479 |
| FMR LLC | 3.2% | 2,145,183 | +9.8% | 0.01% | $216,642,009 |
| STATE STREET CORP | 3.1% | 2,028,651 | +6.3% | 0.01% | $204,873,464 |
| GOLDMAN SACHS GROUP INC | 2.9% | 1,893,663 | +9.2% | 0.03% | $191,241,026 |
| FEDERATED HERMES, INC. | 2.6% | 1,727,885 | +2.5% | 0.31% | $174,499,106 |
| PRICE T ROWE ASSOCIATES INC /MD/ | 2.1% | 1,399,897 | +4.4% | 0.02% | $141,377,000 |
| Driehaus Capital Management LLC | 2.1% | 1,383,775 | +9% | 1% | $139,747,437 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.1% | 1,362,829 | +3.9% | 0.01% | $137,654,057 |
| Polar Capital Holdings Plc | 1.9% | 1,244,932 | -0.47% | 0.61% | $125,725,683 |
| JPMORGAN CHASE & CO | 1.8% | 1,188,069 | +52% | 0.01% | $119,983,088 |
| JANUS HENDERSON GROUP PLC | 1.7% | 1,160,887 | -18% | 0.05% | $117,237,978 |
| WESTFIELD CAPITAL MANAGEMENT CO LP | 1.6% | 1,069,004 | -34% | 0.45% | $107,958,714 |
| ALKEON CAPITAL MANAGEMENT LLC | 1.5% | 1,017,700 | 0% | 0.46% | $102,777,523 |
| ALLIANCEBERNSTEIN L.P. | 1.5% | 979,682 | +1494% | 0.03% | $98,938,085 |
| Checkpoint Capital L.P. | 1.2% | 763,707 | -28% | 26% | $77,126,770 |
| Rock Springs Capital Management LP | 1.1% | 717,102 | -17% | 4.2% | $72,420,131 |
| Pictet Asset Management Holding SA | 1% | 683,017 | +64% | 0.07% | $68,952,135 |
| Capital Research Global Investors | 0.9% | 598,247 | 0.01% | $60,416,965 | |
| Woodline Partners LP | 0.87% | 580,183 | +13% | 0.28% | $58,592,681 |
| Period | Reported Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2025 Q4 | 60,771 | $6,505,171 | -$27,594,973 | $107.04 | 15 |
| 2025 Q3 | 70,889,646 | $7,159,045,368 | +$449,473,140 | $100.99 | 262 |
| 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 |
| 2019 Q4 | 42,379,694 | $973,032,101 | +$189,224,828 | $22.96 | 89 |
| 2019 Q3 | 34,304,970 | $740,632,813 | +$64,825,672 | $21.59 | 84 |
| 2019 Q2 | 31,264,637 | $687,757,946 | +$9,100,651 | $22.00 | 83 |
| 2019 Q1 | 30,865,613 | $846,116,903 | -$21,936,591 | $27.41 | 85 |
| 2018 Q4 | 31,656,641 | $850,986,460 | +$12,828,367 | $26.88 | 73 |
| 2018 Q3 | 31,142,295 | $908,421,537 | +$2,062,008 | $29.17 | 77 |
| 2018 Q2 | 31,030,594 | $970,020,757 | +$215,509,581 | $31.26 | 84 |
| 2018 Q1 | 24,362,024 | $405,654,613 | -$5,856,715 | $19.90 | 54 |
| 2017 Q4 | 21,624,878 | $628,421,658 | +$507,347,658 | $29.06 | 65 |