Company · Ownership research

RHYTHM PHARMACEUTICALS, INC. RYTM

CIK 0001649904 · CUSIP 76243J105

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 76243J105 (RYTM), not CUSIP 76243J955 (RYTM), CUSIP 76243J905 (RYTM), and does not merge CUSIPs.

This page lists the top 20 of 265 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	BlackRock, Inc. CIK 2012383 · View history	$636.46M 6,302,215 shares	0.01%	+34.68K(+0.60%)Added	SEC filing ↗ Nov 12, 2025	▾
02	RA CAPITAL MANAGEMENT, L.P. CIK 1346824 · View history	$573.76M 5,681,359 shares	7.07%	+120.00K(+2.20%)Added	SEC filing ↗ Nov 14, 2025	▾
03	BAKER BROS. ADVISORS LP CIK 1263508 · View history	$566.00M 5,604,483 shares	4.09%	0(0.00%)Unchanged	SEC filing ↗ Nov 14, 2025	▾
04	VANGUARD GROUP INC CIK 102909 · View history	$504.59M 4,996,427 shares	0.01%	+1.41M(+39.20%)Added	SEC filing ↗ Nov 7, 2025	▾
05	PRIMECAP MANAGEMENT CO/CA/ CIK 763212 · View history	$430.51M 4,262,859 shares	0.33%	-615.18K(-12.60%)Reduced	SEC filing ↗ Nov 12, 2025	▾
06	NEA Management Company, LLC CIK 1512848 · View history	$293.88M 2,909,956 shares	16.13%	0(0.00%)Unchanged	SEC filing ↗ Nov 14, 2025	▾
07	PERCEPTIVE ADVISORS LLC CIK 1224962 · View history	$288.39M 419,104,969 shares	8.33%	+416.69M(+17,230.60%)Added	SEC filing ↗ Nov 14, 2025	▾
08	FMR LLC CIK 315066 · View history	$216.64M 2,145,183 shares	0.01%	+191.74K(+9.80%)Added	SEC filing ↗ Nov 13, 2025	▾
09	STATE STREET CORP CIK 93751 · View history	$204.87M 2,028,651 shares	0.01%	+121.05K(+6.30%)Added	SEC filing ↗ Nov 14, 2025	▾
10	GOLDMAN SACHS GROUP INC CIK 886982 · View history	$191.24M 1,893,663 shares	0.03%	+159.94K(+9.20%)Added	SEC filing ↗ Nov 14, 2025	▾
11	FEDERATED HERMES, INC. CIK 1056288 · View history	$174.50M 1,727,885 shares	0.31%	+41.39K(+2.50%)Added	SEC filing ↗ Nov 3, 2025	▾
12	PRICE T ROWE ASSOCIATES INC /MD/ CIK 80255 · View history	$141.38M 1,399,897 shares	0.02%	+58.51K(+4.40%)Added	SEC filing ↗ Nov 14, 2025	▾
13	Driehaus Capital Management LLC CIK 938206 · View history	$139.75M 1,383,775 shares	1.00%	+113.82K(+9.00%)Added	SEC filing ↗ Nov 14, 2025	▾
14	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$137.65M 1,362,829 shares	0.01%	+51.58K(+3.90%)Added	SEC filing ↗ Nov 12, 2025	▾
15	Polar Capital Holdings Plc CIK 1837309 · View history	$125.73M 1,244,932 shares	0.61%	-5.94K(-0.50%)Reduced	SEC filing ↗ Nov 14, 2025	▾
16	JPMORGAN CHASE & CO CIK 19617 · Amended · View history	$119.98M 1,188,069 shares	0.01%	+404.51K(+51.60%)Added	SEC filing ↗ Nov 26, 2025	▾
17	JANUS HENDERSON GROUP PLC CIK 1274173 · View history	$117.24M 1,160,887 shares	0.05%	-251.01K(-17.80%)Reduced	SEC filing ↗ Nov 14, 2025	▾
18	WESTFIELD CAPITAL MANAGEMENT CO LP CIK 1177719 · View history	$107.96M 1,069,004 shares	0.45%	-560.46K(-34.40%)Reduced	SEC filing ↗ Nov 12, 2025	▾
19	ALKEON CAPITAL MANAGEMENT LLC CIK 1230239 · View history	$102.78M 1,017,700 shares	0.46%	0(0.00%)Unchanged	SEC filing ↗ Nov 14, 2025	▾
20	ALLIANCEBERNSTEIN L.P. CIK 1109448 · View history	$98.94M 979,682 shares	0.03%	+918.21K(+1,493.80%)Added	SEC filing ↗ Nov 14, 2025	▾

Showing 20 / 265 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

265

Cancelled or null records excluded

Disclosed shares

487,553,182

Not deduplicated across managers

Disclosed value

$7.20B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

RHYTHM PHARMACEUTICALS, INC. · Q3 2025

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.