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Rhythm Pharmaceuticals, Inc. (RYTM) institutional ownership

Market cap$5.8B SectorHealthcare
Funds holding · Q1 2026
294
reported RYTM position changes
Top owners · Q1 2026
No disclosed owners are available.
Institutional activity · Q1 2026
Activity unavailable N/A
155 buyers · 139 sellers

Rhythm Pharmaceuticals, Inc. (RYTM) price and institutional activity

Dates

Q1 2026

$0 bought by 155 investors
Citadel Advisors LLCWestfield Capital Management Co LP +153 more
$0 sold by 139 investors
Nea Management Company, LLCJennison Associates LLC +137 more
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Bought Sold Totals per quarter; hover a bar for the names.

Rhythm Pharmaceuticals, Inc. (RYTM) institutional activity · 294

Investor Type Est. change Change Δ Own Date
Nea Management Company, LLC · Exited
Change −2.9M Δ Own −100.0% Date Q1 2026
Nea Management Company, LLC Exited· Q1 2026 −2.9M −100.0% Q1 2026
Citadel Advisors LLC Added· Q1 2026 +1.3M +825.3% Q1 2026
Jennison Associates LLC · Exited
Change −919K Δ Own −100.0% Date Q1 2026
Jennison Associates LLC Exited· Q1 2026 −919K −100.0% Q1 2026
Driehaus Capital Management LLC · Reduced
Change −849K Date Q1 2026
Driehaus Capital Management LLC Reduced· Q1 2026 −849K Q1 2026
Westfield Capital Management Co LP · Added
Change +662K Date Q1 2026
Westfield Capital Management Co LP Added· Q1 2026 +662K Q1 2026
Polar Capital Holdings PLC · Added
Change +430K Date Q1 2026
Polar Capital Holdings PLC Added· Q1 2026 +430K Q1 2026
Point72 Asset Management, L.P. · Added
Change +417K Δ Own +97.2% Date Q1 2026
Point72 Asset Management, L.P. Added· Q1 2026 +417K +97.2% Q1 2026
Bank of America Corp · Added
Change +404K Date Q1 2026
Bank of America Corp Added· Q1 2026 +404K Q1 2026
Federated Hermes, Inc. · Reduced
Change −338K Date Q1 2026
Federated Hermes, Inc. Reduced· Q1 2026 −338K Q1 2026
Vanguard · Added
Change +314K Date Q1 2026
Vanguard Added· Q1 2026 +314K Q1 2026
Braidwell LP · New
Change +311K Date Q1 2026
Braidwell LP New· Q1 2026 +311K Q1 2026
Lord, Abbett & Co. LLC · Reduced
Change −271K Date Q1 2026
Lord, Abbett & Co. LLC Reduced· Q1 2026 −271K Q1 2026
Millennium Management LLC · Added
Change +265K Date Q1 2026
Millennium Management LLC Added· Q1 2026 +265K Q1 2026
Logos Global Management LP · Added
Change +260K Date Q1 2026
Logos Global Management LP Added· Q1 2026 +260K Q1 2026
Checkpoint Capital L.P. · Added
Change +235K Date Q1 2026
Checkpoint Capital L.P. Added· Q1 2026 +235K Q1 2026
Data through Q1 2026 · filed Jun 2, 2026
15 of 294

Famous investor activity in Rhythm Pharmaceuticals, Inc. (RYTM)

Rhythm Pharmaceuticals, Inc. (RYTM) insider trading

Company insiders, action and economics first; trade and filed dates last.
Dates
Insider Title Type Price Qty Value Owned ΔOwn Trade date Filed date
Garfield Alastair · Officer 2 operations 0
Owned 9K Trade date Jul 1, 2026 Filed date Jul 2, 2026
Garfield Alastair Officer 2 operations 0 9K Jul 1, 2026 Jul 2, 2026
Garfield Alastair · Officer Tax withholding or exercise payment (F) -$237K
Price $110.41 Qty -2K Owned 10K ΔOwn −17.6% Trade date Jul 1, 2026 Filed date Jul 2, 2026
Garfield Alastair Officer Tax withholding or exercise payment (F) $110.41 -2K -$237K 10K −17.6% Jul 1, 2026 Jul 2, 2026
Jean Christophe · Director 2 operations 6K
Owned 2K Trade date Jun 24, 2026 Filed date Jun 25, 2026
Jean Christophe Director 2 operations 6K 2K Jun 24, 2026 Jun 25, 2026
McGirr David W. J. · Director 2 operations 6K
Owned 2K Trade date Jun 24, 2026 Filed date Jun 25, 2026
McGirr David W. J. Director 2 operations 6K 2K Jun 24, 2026 Jun 25, 2026
Tetrault Lynn A. · Director 2 operations 6K
Owned 2K Trade date Jun 24, 2026 Filed date Jun 25, 2026
Tetrault Lynn A. Director 2 operations 6K 2K Jun 24, 2026 Jun 25, 2026
Arbuckle Stuart A. · Director 2 operations 6K
Owned 2K Trade date Jun 24, 2026 Filed date Jun 25, 2026
Arbuckle Stuart A. Director 2 operations 6K 2K Jun 24, 2026 Jun 25, 2026
Good Jennifer L. · Director 2 operations 6K
Owned 2K Trade date Jun 24, 2026 Filed date Jun 25, 2026
Good Jennifer L. Director 2 operations 6K 2K Jun 24, 2026 Jun 25, 2026
Jean Christophe · Director 2 operations 0
Owned 0 Trade date Jun 23, 2026 Filed date Jun 25, 2026
Jean Christophe Director 2 operations 0 0 Jun 23, 2026 Jun 25, 2026
McGirr David W. J. · Director 2 operations 0
Owned 0 Trade date Jun 23, 2026 Filed date Jun 25, 2026
McGirr David W. J. Director 2 operations 0 0 Jun 23, 2026 Jun 25, 2026
Tetrault Lynn A. · Director 2 operations 0
Owned 0 Trade date Jun 23, 2026 Filed date Jun 25, 2026
Tetrault Lynn A. Director 2 operations 0 0 Jun 23, 2026 Jun 25, 2026
Arbuckle Stuart A. · Director 2 operations 0
Owned 0 Trade date Jun 23, 2026 Filed date Jun 25, 2026
Arbuckle Stuart A. Director 2 operations 0 0 Jun 23, 2026 Jun 25, 2026
Good Jennifer L. · Director 2 operations 0
Owned 0 Trade date Jun 23, 2026 Filed date Jun 25, 2026
Good Jennifer L. Director 2 operations 0 0 Jun 23, 2026 Jun 25, 2026
Tetrault Lynn A. · Director Sell −$3.7M
Price $100.32 Qty −37K Owned 7K ΔOwn −84.1% Trade date Jun 22, 2026 Filed date Jun 24, 2026
Tetrault Lynn A. Director Sell $100.32 −37K −$3.7M 7K −84.1% Jun 22, 2026 Jun 24, 2026
Tetrault Lynn A. · Director 2 operations 0
Price $28.27 Owned 0 Trade date Jun 22, 2026 Filed date Jun 24, 2026
Tetrault Lynn A. Director 2 operations $28.27 0 0 Jun 22, 2026 Jun 24, 2026
Smith Hunter C. · CFO 2 operations 0
Price $17.87 Owned 79K Trade date May 18, 2026 Filed date May 20, 2026
Smith Hunter C. CFO 2 operations $17.87 0 79K May 18, 2026 May 20, 2026
15 of 58
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Rhythm Pharmaceuticals, Inc. (RYTM) activist and large shareholders

What are Schedules 13D and 13G?

Dates
Owner/Filer identity Shares reported % of shares outstanding Filing date
Primecap Management Co 7.2M
% of shares outstanding 11.8% Filing date Nov 12, 2024
Primecap Management Co 7.2M 11.8% Nov 12, 2024
Baker Bros. Advisors LP 6.4M
% of shares outstanding 10.8% Filing date Feb 14, 2024
Baker Bros. Advisors LP 6.4M 10.8% Feb 14, 2024
BlackRock Inc. 6.4M
% of shares outstanding 10.7% Filing date Jan 24, 2024
BlackRock Inc. 6.4M 10.7% Jan 24, 2024
Ra Capital Management, L.P. 6.1M
% of shares outstanding 9.9% Filing date Nov 14, 2024
Ra Capital Management, L.P. 6.1M 9.9% Nov 14, 2024
Goldman Sachs Group Inc 3.9M
% of shares outstanding 6.4% Filing date Nov 12, 2024
Goldman Sachs Group Inc 3.9M 6.4% Nov 12, 2024
Vanguard Group Inc 3.2M
% of shares outstanding 5.5% Filing date Feb 13, 2024
Vanguard Group Inc 3.2M 5.5% Feb 13, 2024
Perceptive Advisors LLC 3.5M
% of shares outstanding 5.1% Filing date May 15, 2026
Perceptive Advisors LLC 3.5M 5.1% May 15, 2026
New Enterprise Associates 13 LP 2.9M
% of shares outstanding 5.1% Filing date Mar 29, 2023
New Enterprise Associates 13 LP 2.9M 5.1% Mar 29, 2023
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Rhythm Pharmaceuticals, Inc. (RYTM) ownership FAQ

Who owns RYTM?

294 reporting institutions disclosed RYTM position changes in the Q1 2026 snapshot.

How is institutional activity calculated?

For each manager, WhoBought compares accepted consecutive 13F share counts. Share change is current shares minus prior shares. Estimated dollar change is that signed share change multiplied by the split-adjusted quarter-mean close. The activity table on this page uses Q1 2026.

What are activist and large shareholder filings?

An investor crossing 5% of a share class generally files Schedule 13D for activist intent or Schedule 13G for a passive position. The technical form names appear here rather than in the activity rows.

Where does this data come from?

Ownership and institutional activity come from SEC Form 13F filings. Insider activity comes from SEC Form 4, and large-shareholder activity from SEC Schedules 13D and 13G. FMP supplies price data only. Company logos use the local verified Parqet cache with one shared fallback.

Why are ownership reports delayed?

Form 13F is a quarterly disclosure and is normally filed after the quarter ends. Every ownership and activity value therefore names its represented period; it is not presented as a live position.

How are missing table values shown?

A muted dash marks a missing table value. It means the filing omitted the value, comparable data is unavailable, or no prior position exists for comparison.