RHYTHM PHARMACEUTICALS INC (RYTM) Institutional Shareholders
RHYTHM PHARMACEUTICALS INC (RYTM) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $8.44B in RYTM holdings during the latest filing period.
Ra Capital Management, L.P. is currently the largest disclosed institutional shareholder of RYTM tracked by InsiderSet, reporting ownership valued at approximately $740.22M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $653.42M, representing an estimated loss of -11.73% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 50% of the total disclosed RYTM value among the investors covered in this analysis. Major shareholders include Ra Capital Management, L.P., Blackrock, Inc., Baker Bros. Advisors Lp, and several other long-term asset managers with concentrated positions in RHYTHM PHARMACEUTICALS INC (RYTM).
This page ranks the largest institutional RYTM shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
291
Total Reported Value
$8.44B
Largest Holder
Ra Capital Management, L.P.
Largest Position
$740.22M
Insider Transactions (90d)
34
Latest Filing Quarter
Q2 2026
New Institutional Positions
52
Funds Exiting Positions
1
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Ra Capital Management, L.P. | 6.43% | 6,666,837 | $740,218,912 | $653,416,694 | -$86,802,218 | -11.73% | |
| Blackrock, Inc. | 0.01% | 6,156,902 | $683,600,828 | $603,437,965 | -$80,162,863 | -11.73% | |
| Baker Bros. Advisors Lp | 3.12% | 5,604,483 | $622,265,747 | $549,295,379 | -$72,970,368 | -11.73% | |
| Primecap Management Co/Ca/ | 0.21% | 3,168,853 | $351,837,748 | $310,579,283 | -$41,258,465 | -11.73% | |
| Vanguard Portfolio Management Llc | 0.02% | 3,136,895 | $348,289,452 | $307,447,079 | -$40,842,373 | -11.73% | |
| Vanguard Capital Management Llc | 0.01% | 3,005,977 | $333,753,626 | $294,615,806 | -$39,137,820 | -11.73% | |
| Jpmorgan Chase & Co | 0.02% | 2,652,746 | $292,178,898 | $259,995,635 | -$32,183,263 | -11.01% | |
| Perceptive Advisors Llc | 4.46% | 2,586,295 | $287,156,334 | $253,482,773 | -$33,673,561 | -11.73% | |
| State Street Corp | 0.01% | 2,573,529 | $285,728,722 | $252,231,577 | -$33,497,145 | -11.72% | |
| Price T Rowe Associates Inc | 0.03% | 2,566,171 | $284,923,000 | $251,510,420 | -$33,412,580 | -11.73% | |
| Westfield Capital Management Co Lp | 0.80% | 2,208,595 | $245,220,303 | $216,464,396 | -$28,755,907 | -11.73% | |
| Goldman Sachs Group Inc | 0.02% | 2,126,502 | $236,105,516 | $208,418,461 | -$27,687,055 | -11.73% | |
| Federated Hermes, Inc. | 0.29% | 1,785,716 | $198,268,047 | $175,018,025 | -$23,250,022 | -11.73% | |
| Polar Capital Holdings Plc | 0.52% | 1,663,632 | $184,713,061 | $163,052,572 | -$21,660,489 | -11.73% | |
| Geode Capital Management, Llc | 0.01% | 1,533,698 | $170,320,392 | $150,317,741 | -$20,002,651 | -11.74% | |
| Capital Research Global Investors | 0.02% | 1,532,303 | $170,131,602 | $150,181,017 | -$19,950,585 | -11.73% | |
| Citadel Advisors Llc | 0.08% | 1,263,652 | $140,303,282 | $123,850,533 | -$16,452,749 | -11.73% | |
| Checkpoint Capital L.P. | 33.79% | 1,186,000 | $131,681,580 | $116,239,860 | -$15,441,720 | -11.73% | |
| Siren, L.L.C. | 2.56% | 1,136,275 | $126,160,613 | $111,366,313 | -$14,794,300 | -11.73% | |
| Morgan Stanley | 0.01% | 1,112,240 | $123,492,178 | $109,010,642 | -$14,481,536 | -11.73% | |
| Fmr Llc | 0.00% | 1,025,840 | $113,899,059 | $100,542,578 | -$13,356,481 | -11.73% | |
| Pictet Asset Management Holding Sa | 0.10% | 957,785 | $106,252,095 | $93,872,508 | -$12,379,587 | -11.65% | |
| Woodline Partners Lp | 0.26% | 758,891 | $84,259,668 | $74,378,907 | -$9,880,761 | -11.73% | |
| Janus Henderson Group Plc | 0.04% | 918,153 | $79,886,248 | $89,988,176 | +$10,101,928 | +12.65% | |
| Alliancebernstein L.P. | 0.03% | 894,723 | $77,814,059 | $87,691,801 | +$9,877,742 | +12.69% | |
| Clearbridge Investments, Llc | 0.06% | 696,473 | $77,329,368 | $68,261,319 | -$9,068,049 | -11.73% | |
| Rock Springs Capital Management Lp | 3.75% | 692,598 | $76,899,156 | $67,881,530 | -$9,017,626 | -11.73% | |
| Norges Bank | 0.01% | 685,844 | $76,149,259 | $67,219,570 | -$8,929,689 | -11.73% | |
| Charles Schwab Investment Management Inc | 0.01% | 552,738 | $61,370,500 | $54,173,851 | -$7,196,649 | -11.73% | |
| Integral Health Asset Management, Llc | 2.51% | 550,000 | $61,066,500 | $53,905,500 | -$7,161,000 | -11.73% | |
| Invesco Ltd. | 0.00% | 543,271 | $60,319,379 | $53,245,991 | -$7,073,388 | -11.73% | |
| Northern Trust Corp | 0.01% | 540,332 | $59,993,061 | $52,957,939 | -$7,035,122 | -11.73% | |
| Wellington Management Group Llp | 0.01% | 488,747 | $54,265,580 | $47,902,093 | -$6,363,487 | -11.73% | |
| Vanguard Fiduciary Trust Co | 0.01% | 445,723 | $49,488,625 | $43,685,311 | -$5,803,314 | -11.73% | |
| Loomis Sayles & Co L P | 0.06% | 434,102 | $48,198,345 | $42,546,337 | -$5,652,008 | -11.73% | |
| Candriam S.C.A. | 0.22% | 433,025 | $48,032,508 | $42,440,780 | -$5,591,728 | -11.64% | |
| Ubs Am, A Distinct Business Unit Of Ubs Asset Management Americas Llc | 0.01% | 541,450 | $47,089,907 | $53,067,515 | +$5,977,608 | +12.69% | |
| Squarepoint Ops Llc | 0.09% | 422,921 | $46,956,919 | $41,450,487 | -$5,506,432 | -11.73% | |
| Point72 Asset Management, L.P. | 0.07% | 414,210 | $45,989,736 | $40,596,722 | -$5,393,014 | -11.73% | |
| Sofinnova Investments, Inc. | 2.42% | 408,027 | $45,303,238 | $39,990,726 | -$5,312,512 | -11.73% | |
| Ameriprise Financial Inc | 0.01% | 401,634 | $44,593,674 | $39,364,148 | -$5,229,526 | -11.73% | |
| Adage Capital Partners Gp, L.L.C. | 0.06% | 397,000 | $44,078,910 | $38,909,970 | -$5,168,940 | -11.73% | |
| Bank Of New York Mellon Corp | 0.01% | 394,044 | $43,750,776 | $38,620,252 | -$5,130,524 | -11.73% | |
| Braidwell Lp | 1.57% | 381,128 | $42,316,642 | $37,354,355 | -$4,962,287 | -11.73% | |
| Artisan Partners Limited Partnership | 0.06% | 354,816 | $39,395,220 | $34,775,516 | -$4,619,704 | -11.73% | |
| Bank Of America Corp | 0.00% | 325,470 | $36,136,934 | $31,899,315 | -$4,237,619 | -11.73% | |
| Orbimed Advisors Llc | 0.68% | 322,900 | $35,851,587 | $31,647,429 | -$4,204,158 | -11.73% | |
| Millennium Management Llc | 0.02% | 316,719 | $35,165,311 | $31,041,629 | -$4,123,682 | -11.73% | |
| Silverarc Capital Management, Llc | 3.85% | 311,461 | $34,581,515 | $30,526,293 | -$4,055,222 | -11.73% | |
| Voya Investment Management Llc | 0.03% | 272,974 | $30,308,303 | $26,754,182 | -$3,554,121 | -11.73% |
Frequently asked questions about RYTM
Who owns the most RYTM stock?
The largest holders of RYTM are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for RHYTHM PHARMACEUTICALS INC (RYTM).
Is RYTM widely held by superinvestors?
Many widely followed stocks like RYTM appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly RYTM is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.