Security record · archived quarter
RYTM
Rhythm Pharmaceuticals, Inc. · Healthcare · Biotechnology
109Tracked holders
+6Δ holders
41.83MShares held
$3.64BReported value
+11New positions
−6Exits
Momentum inputs (comparable managers):
holder breadth +5.8% ·
share flow +4.7% ·
net new positions +4.6%
— formula
Broad accumulation — rising shares across more holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q1 2026
Ownership over time
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 113 | +6 | 44.38M | $4.90B | +14 | −7 |
| Q1 2026 | 109 | +6 | 41.83M | $3.64B | +11 | −6 |
| Q4 2025 | 102 | 0 | 43.14M | $4.62B | +3 | −2 |
| Q3 2025 | 20 | +1 | 28.88M | $2.92B | +2 | −2 |
| Q2 2025 | 17 | 0 | 22.96M | $1.45B | +1 | −1 |
| Q1 2025 | 14 | +2 | 11.52M | $610.22M | +2 | — |
| Q4 2024 | 12 | 0 | 11.40M | $638.39M | — | — |
| Q3 2024 | 11 | +3 | 9.71M | $508.75M | +3 | — |
| Q2 2024 | 8 | — | 9.56M | $392.54M | — | — |
Who holds it · Q1 2026
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 2 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 3 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 4 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 5 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 6 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 7 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 8 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 9 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 10 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 11 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 12 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 13 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 14 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 15 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 16 | BlackRock ✦ (passive) | 6.24M | -1.0% | $542.45M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 17 | PRIMECAP Management ✦ | 3.42M | -1.8% | $297.22M | 0.2% | ▼ Trim | 8 | SEC ↗ |
| 18 | Vanguard Capital Management Llc | 2.97M | — | $258.11M | 0.0% | n/c | 1 | SEC ↗ |
| 19 | State Street Global Advisors ✦ (passive) | 2.27M | +3.3% | $197.58M | 0.0% | ▲ Add | 6 | SEC ↗ |
| 20 | Goldman Sachs Group ✦ | 1.97M | +7.3% | $170.93M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 21 | Goldman Sachs Group ✦ | 1.97M | +7.3% | $170.93M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 22 | Fidelity (FMR) ✦ | 1.69M | -1.0% | $146.95M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 23 | Fidelity (FMR) ✦ | 1.69M | -1.0% | $146.95M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 24 | Fidelity (FMR) ✦ | 1.69M | -1.0% | $146.95M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 25 | Fidelity (FMR) ✦ | 1.69M | -1.0% | $146.95M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 26 | T. Rowe Price ✦ | 1.65M | +6.0% | $143.93M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 27 | T. Rowe Price ✦ | 1.65M | +6.0% | $143.93M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 28 | Citadel Advisors ✦ | 1.42M | +825.2% | $123.38M | 0.1% | ▲ Add | 3 | SEC ↗ |
| 29 | Citadel Advisors ✦ | 1.42M | +825.2% | $123.38M | 0.1% | ▲ Add | 3 | SEC ↗ |
| 30 | Geode Capital Management ✦ (passive) | 1.42M | +3.0% | $123.20M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 31 | Geode Capital Management ✦ (passive) | 1.42M | +3.0% | $123.20M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 32 | JPMorgan Chase ✦ | 1.55M | +9.1% | $120.02M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 33 | JPMorgan Chase ✦ | 1.55M | +9.1% | $120.02M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 34 | JPMorgan Chase ✦ | 1.55M | +9.1% | $120.02M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 35 | JPMorgan Chase ✦ | 1.55M | +9.1% | $120.02M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 36 | JPMorgan Chase ✦ | 1.55M | +9.1% | $120.02M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 37 | JPMorgan Chase ✦ | 1.55M | +9.1% | $120.02M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 38 | Federated Hermes, Inc. | 1.29M | -20.8% | $111.87M | 0.2% | ▼ Trim | 2 | SEC ↗ |
| 39 | Federated Hermes, Inc. | 1.29M | -20.8% | $111.87M | 0.2% | ▼ Trim | 2 | SEC ↗ |
| 40 | Federated Hermes, Inc. | 1.29M | -20.8% | $111.87M | 0.2% | ▼ Trim | 2 | SEC ↗ |
| 41 | Alliancebernstein L.P. | 910.41K | -2.1% | $97.45M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 42 | Capital Research Global Investors | 1.12M | +13.2% | $97.01M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 43 | Janus Henderson Group Plc | 918.15K | -18.5% | $79.89M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 44 | Janus Henderson Group Plc | 918.15K | -18.5% | $79.89M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 45 | Point72 Asset Management ✦ | 846.80K | +97.2% | $73.65M | 0.1% | ▲ Add | 2 | SEC ↗ |
| 46 | Adage Capital Partners ✦ | 725.74K | +16.8% | $63.12M | 0.1% | ▲ Add | 4 | SEC ↗ |
| 47 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 48 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 49 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 50 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 51 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 52 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 53 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 54 | Morgan Stanley ✦ | 703.98K | +8.1% | $61.23M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 55 | Pictet Asset Management Holding SA | 667.05K | +8.5% | $57.33M | 0.1% | ▲ Add | 2 | SEC ↗ |
| 56 | Bank Of America Corp /De/ | 628.67K | +180.1% | $54.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 57 | Bank Of America Corp /De/ | 628.67K | +180.1% | $54.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 58 | Bank Of America Corp /De/ | 628.67K | +180.1% | $54.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 59 | Bank Of America Corp /De/ | 628.67K | +180.1% | $54.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 60 | Bank Of America Corp /De/ | 628.67K | +180.1% | $54.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 61 | Franklin Resources Inc | 626.85K | -9.9% | $54.52M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 62 | Franklin Resources Inc | 626.85K | -9.9% | $54.52M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 63 | Franklin Resources Inc | 626.85K | -9.9% | $54.52M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 64 | Franklin Resources Inc | 626.85K | -9.9% | $54.52M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 65 | Franklin Resources Inc | 626.85K | -9.9% | $54.52M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 66 | Franklin Resources Inc | 626.85K | -9.9% | $54.52M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 67 | Clearbridge Investments, LLC | 609.44K | +20.4% | $53.00M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 68 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 69 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 70 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 71 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 72 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 73 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 74 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 75 | UBS AM, a distinct business unit of… | 541.45K | -1.4% | $47.09M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 76 | Charles Schwab Investment… | 526.46K | -1.1% | $45.79M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 77 | Northern Trust Corp | 498.51K | +2.1% | $43.36M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 78 | Northern Trust Corp | 498.51K | +2.1% | $43.36M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 79 | Northern Trust Corp | 498.51K | +2.1% | $43.36M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 80 | Northern Trust Corp | 498.51K | +2.1% | $43.36M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 81 | Northern Trust Corp | 498.51K | +2.1% | $43.36M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 82 | Loomis Sayles & Co L P | 465.10K | -7.7% | $40.45M | 0.1% | ▼ Trim | 2 | SEC ↗ |
| 83 | Loomis Sayles & Co L P | 465.10K | -7.7% | $40.45M | 0.1% | ▼ Trim | 2 | SEC ↗ |
| 84 | Millennium Management ✦ | 451.82K | +142.0% | $39.30M | 0.0% | ▲ Add | 7 | SEC ↗ |
| 85 | Artisan Partners Limited Partnership | 390.67K | +48.2% | $33.98M | 0.1% | ▲ Add | 2 | SEC ↗ |
| 86 | Ameriprise Financial Inc | 383.96K | +47.0% | $33.39M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 87 | Ameriprise Financial Inc | 383.96K | +47.0% | $33.39M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 88 | Ameriprise Financial Inc | 383.96K | +47.0% | $33.39M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 89 | Ameriprise Financial Inc | 383.96K | +47.0% | $33.39M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 90 | Ameriprise Financial Inc | 383.96K | +47.0% | $33.39M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 91 | Invesco Ltd. | 364.31K | +25.1% | $31.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 92 | Invesco Ltd. | 364.31K | +25.1% | $31.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 93 | Invesco Ltd. | 364.31K | +25.1% | $31.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 94 | Invesco Ltd. | 364.31K | +25.1% | $31.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 95 | Invesco Ltd. | 364.31K | +25.1% | $31.68M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 96 | Bank of New York Mellon Corp | 293.30K | -2.6% | $25.51M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 97 | Bank of New York Mellon Corp | 293.30K | -2.6% | $25.51M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 98 | Bank of New York Mellon Corp | 293.30K | -2.6% | $25.51M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 99 | Bank of New York Mellon Corp | 293.30K | -2.6% | $25.51M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 100 | Bank of New York Mellon Corp | 293.30K | -2.6% | $25.51M | 0.0% | ▼ Trim | 2 | SEC ↗ |
“Their weight” = the position's share of that manager's reported 13F equity value — the conviction measure. ✦ = curated manager.
New buyers
| No new tracked buyers this quarter. |
Exited
| Jennison Associates Llc | $98.32M | was 0.1% |
| Norges Bank | $7.09M | was 0.0% |
| Mackenzie Financial Corp | $468,607 | was 0.0% |
| Tidal Investments LLC | $357,085 | was 0.0% |
| Jane Street Group, Llc | $209,798 | was 0.0% |
| Daiwa Securities Group Inc. | $22,000 | was 0.0% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 284 holders, 72.02M shares, $6.12B reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
Frequently co-owned
What else this security's tracked holders most often hold — shared-ownership counts, not fundamental relationships.
Open-market purchases (P)
No open-market insider purchases in our coverage window.
Open-market sales (S)
Aug 13
Garfield Alastair
Officer · 2.01K sh · $233,031
Aug 13
Garfield Alastair
Officer · 1.56K sh · $182,170
Aug 13
Garfield Alastair
Officer · 3.40K sh · $402,167
Aug 13
Garfield Alastair
Officer · 800 sh · $95,335
Aug 13
Lee Jennifer Kayden
Officer · 75.83K sh · $8.90M
Aug 12
Mazabraud Yann
Officer · 2.30K sh · $257,138
Aug 12
Mazabraud Yann
Officer · 1.00K sh · $112,856
Aug 12
Mazabraud Yann
Officer · 3.60K sh · $413,477
Aug 12
Mazabraud Yann
Officer · 14.57K sh · $1.68M
Aug 12
Mazabraud Yann
Officer · 18.21K sh · $2.12M
Awards, exercises and tax withholding are never counted as buys or sales here. Methodology
Provenance: Ownership from parsed 13F common-stock positions (tracked universe, comparable sets for changes); insider rows from Forms 3/4/5; stakes from Schedules 13D/13G; every filing links to its original on SEC EDGAR.
Reporting period: Q1 2026 ·
Methodology ·
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