Rhythm Pharmaceuticals, Inc. (RYTM) shareholders
RYTMNasdaqPharmaceutical PreparationsFiscal year ends December 31
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Nov 3, 2026Score 5/30265% above fair value
$115.02+5.16 (+4.70%)
Close on Nov 13, 2026Market cap $7.92BP/E –Yield –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
100.0%
77M of 69M shares
Institutional holders
303
64 new, 41 sold out
Net institutional buying
5M
In Q2 2026
Insider trades, 12 months
0 buys · 48 sales
Net sold $36.38M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Peter Kolchinsky Joint filing with RA Capital Management, L.P. (9.90%), Rajeev Shah (9.90%) and 1 more | 6,666,837 | 9.90% | 13G (passive) amendment | Dec 31, 2025 |
| Baker Bros. Advisors LP Joint filing with Baker Bros. Advisors (GP) LLC (8.90%), Julian C. Baker (8.90%) and 1 more | 5,604,483 | 8.90% | 13G (passive) amendment | Mar 31, 2025 |
| Rajeev Shah Joint filing with RA Capital Management, L.P. (8.70%), Peter Kolchinsky (8.70%) and 1 more | 5,561,359 | 8.70% | 13G (passive) amendment | Jun 30, 2025 |
| BlackRock, Inc. | 4,364,700 | 6.90% | 13G (passive) amendment | Mar 31, 2025 |
| JPMorgan Chase & Co. | 3,563,667 | 5.10% | 13G (passive) | Sep 30, 2026 |
| Perceptive Advisors LLC Joint filing with Joseph Edelman (5.10%) | 3,519,626 | 5.10% | 13G (passive) amendment | Mar 31, 2026 |
| Primecap Management Co/Ca/ | 3,478,669 | 5.21% | 13G (passive) amendment | Dec 31, 2025 |
| Vanguard Capital Management | 3,432,949 | 5.02% | 13G (passive) | Mar 31, 2026 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of RYTM | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| Ra Capital Management, L.P. | 6,666,837 | 9.68% | $740.22M | – | 6.43% |
| BlackRock, Inc. | 6,156,902 | 8.94% | $683.60M | −80,249 | 0.01% |
| Baker Bros. Advisors LP | 5,604,483 | 8.14% | $622.27M | – | 3.12% |
| Primecap Management Co/Ca/ | 3,168,853 | 4.60% | $351.84M | −248,656 | 0.21% |
| Vanguard Portfolio Management LLC | 3,136,895 | 4.56% | $348.29M | +96,177 | 0.02% |
| Vanguard Capital Management LLC | 3,005,977 | 4.37% | $333.75M | +38,152 | 0.01% |
| JPMorgan Chase & Co | 2,652,746 | 3.85% | $292.18M | +1,099,102 | 0.02% |
| Perceptive Advisors LLC | 2,586,295 | 3.76% | $287.16M | +212,500 | 4.31% |
| State Street Corp | 2,573,529 | 3.74% | $285.73M | +301,678 | 0.01% |
| Price T Rowe Associates Inc /Md/ | 2,566,171 | 3.73% | $284.92M | +911,295 | 0.03% |
| Westfield Capital Management Co LP | 2,208,595 | 3.21% | $245.22M | +279,472 | 0.80% |
| Goldman Sachs Group Inc | 2,126,502 | 3.09% | $236.11M | +161,070 | 0.02% |
| Federated Hermes, Inc. | 1,785,716 | 2.59% | $198.27M | +499,413 | 0.29% |
| Polar Capital Holdings Plc | 1,663,632 | 2.42% | $184.71M | +48,046 | 0.44% |
| Geode Capital Management, LLC | 1,533,698 | 2.23% | $170.32M | +117,429 | 0.01% |
| Capital Research Global Investors | 1,532,303 | 2.23% | $170.13M | +416,843 | 0.02% |
| Citadel Advisors LLC | 1,263,652 | 1.84% | $140.30M | −154,967 | 0.02% |
| Checkpoint Capital L.P. | 1,186,000 | 1.72% | $131.68M | −41,200 | 33.79% |
| Siren, L.L.C. | 1,136,275 | 1.65% | $126.16M | +410,764 | 2.55% |
| Morgan Stanley | 1,112,240 | 1.62% | $123.49M | +408,262 | 0.01% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 303 | 77M | 100.0% | 64 / 105 | 101 / 41 | 10M | 6M |
| Q1 2026 | 285 | 74M | 100.0% | 63 / 102 | 89 / 54 | 15M | 8M |
| Q4 2025 | 281 | 73M | 100.0% | 58 / 106 | 90 / 39 | 8M | 7M |
| Q3 2025 | 264 | 72M | 100.0% | 57 / 99 | 82 / 17 | 10M | 5M |
| Q2 2025 | 227 | 67M | 96.9% | 33 / 93 | 74 / 33 | 8M | 6M |
| Q1 2025 | 228 | 65M | 94.3% | 45 / 87 | 69 / 19 | 8M | 7M |
| Q4 2024 | 203 | 65M | 94.3% | 52 / 67 | 53 / 24 | 4M | 7M |
| Q3 2024 | 176 | 68M | 98.4% | 31 / 60 | 55 / 19 | 11M | 6M |
| Q2 2024 | 165 | 70M | 100.0% | 24 / 62 | 55 / 24 | 5M | 5M |
| Q1 2024 | 167 | 69M | 99.8% | 25 / 64 | 53 / 26 | 6M | 5M |
| Q4 2023 | 168 | 67M | 97.7% | 44 / 42 | 63 / 19 | 8M | 9M |
| Q3 2023 | 143 | 68M | 99.3% | 39 / 48 | 39 / 12 | 8M | 6M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
329 funds held RYTM in Q2 2026, 36% of their shares through ETFs. Each fund counts once per quarter, from its quarter-end report.
| Fund | Shares | % of RYTM | Value | % of fund | As of |
|---|---|---|---|---|---|
| Vanguard Total Stock Market Index Fund | 2,176,750 | 3.16% | $241.68M | 0.01% | Jun 30, 2026 |
| PRIMECAP Odyssey Aggressive Growth Fund | 1,967,269 | 2.86% | $195.25M | 2.64% | Jul 31, 2026 |
| SMALLCAP World Fund Inc | 1,707,348 | 2.48% | $189.57M | 0.20% | Jun 30, 2026 |
| Vanguard Small-Cap Index Fund | 1,572,293 | 2.28% | $174.57M | 0.09% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 1,416,703 | 2.06% | $157.30M | 0.19% | Jun 30, 2026 |
| State Street(R) SPDR(R) S&P(R) Biotech ETF | 1,161,672 | 1.69% | $128.98M | 1.20% | Jun 30, 2026 |
| Federated Hermes Kaufmann Fund | 1,026,365 | 1.49% | $101.87M | 2.07% | Jul 31, 2026 |
| PRIMECAP Odyssey Growth Fund | 1,008,902 | 1.47% | $100.13M | 1.65% | Jul 31, 2026 |
| Vanguard Small-Cap Growth Index Fund | 905,995 | 1.32% | $100.59M | 0.21% | Jun 30, 2026 |
| T. Rowe Price New Horizons Fund, Inc. | 779,815 | 1.13% | $86.58M | 0.59% | Jun 30, 2026 |
| JPMorgan Mid Cap Growth Fund | 747,736 | 1.09% | $83.02M | 0.63% | Jun 30, 2026 |
| Vanguard Extended Market Index Fund | 715,692 | 1.04% | $79.46M | 0.08% | Jun 30, 2026 |
| Federated Hermes Kaufmann Small Cap Fund | 610,000 | 0.89% | $60.54M | 2.13% | Jul 31, 2026 |
| Fidelity Small Cap Index Fund | 603,209 | 0.88% | $59.87M | 0.18% | Jul 31, 2026 |
| Vanguard Explorer Fund | 559,749 | 0.81% | $55.56M | 0.25% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| David P. Meeker | President and CEO, Director | 289,258 | 0.42% | Sep 14, 2026 |
| Hunter C. Smith | Chief Financial Officer | 114,024 | 0.17% | Sep 1, 2026 |
| Manher Joshi | Chief Medical Officer | – | – | Aug 18, 2026 |
| Joseph Shulman | Chief Technical Officer | 20,994 | 0.03% | Aug 17, 2026 |
| Alastair Garfield | Chief Scientific Officer | 3,095 | 0.00% | Aug 17, 2026 |
| Yann Mazabraud | EVP, Head of International | 105,750 | 0.15% | Aug 14, 2026 |
| Jennifer Kayden Lee | EVP, Head of North America | 75,834 | 0.11% | Aug 14, 2026 |
| Christopher Paul German | Corporate Controller & CAO | 1,888 | 0.00% | May 19, 2026 |
| Pamela J. Cramer | Chief Human Resources Officer | 29,376 | 0.04% | Feb 13, 2026 |
| Lynn A. Tetrault | Director | 11,712 | 0.02% | Jun 25, 2026 |
| Stuart A. Arbuckle | Director | 11,712 | 0.02% | Jun 25, 2026 |
| David W. J. McGirr | Director | 11,712 | 0.02% | Jun 25, 2026 |
| Christophe Jean | Director | 11,712 | 0.02% | Jun 25, 2026 |
| Jennifer L. Good | Director | 11,712 | 0.02% | Jun 25, 2026 |
| Kimberly J. Popovits | Director | – | – | Apr 3, 2026 |
| Edward T. Mathers | Director | 21,168 | 0.03% | Mar 16, 2026 |
| Camille L. Bedrosian | Director | 7,000 | 0.01% | Jun 26, 2025 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| David P. Meeker President and CEO, Director | Sep 14, 2026 | Option exercise | +50,000 | $6.05 | $302.50K | 289,258 |
| David P. Meeker President and CEO, Director | Sep 14, 2026 | Sale(10b5-1 plan) | −1,817 | $104.55 | $189.97K | 241,558 |
| David P. Meeker President and CEO, Director | Sep 14, 2026 | Sale(10b5-1 plan) | −8,698 | $103.43 | $899.63K | 243,375 |
| David P. Meeker President and CEO, Director | Sep 14, 2026 | Sale(10b5-1 plan) | −30,746 | $102.35 | $3.15M | 252,073 |
| David P. Meeker President and CEO, Director | Sep 14, 2026 | Sale(10b5-1 plan) | −6,439 | $101.75 | $655.17K | 282,819 |
| David P. Meeker President and CEO, Director | Sep 14, 2026 | Sale(10b5-1 plan) | −2,300 | $105.19 | $241.94K | 239,258 |
| Hunter C. Smith Chief Financial Officer | Aug 31, 2026 | Sale(10b5-1 plan) | −28,188 | $106.20 | $2.99M | 114,024 |
| Hunter C. Smith Chief Financial Officer | Aug 31, 2026 | Option exercise | +57,187 | $25.79 | $1.47M | 176,798 |
| Hunter C. Smith Chief Financial Officer | Aug 31, 2026 | Sale(10b5-1 plan) | −23,072 | $104.59 | $2.41M | 153,726 |
| Hunter C. Smith Chief Financial Officer | Aug 31, 2026 | Sale(10b5-1 plan) | −11,514 | $105.37 | $1.21M | 142,212 |
| Alastair Garfield Chief Scientific Officer | Aug 13, 2026 | Sale(10b5-1 plan) | −3,400 | $118.28 | $402.15K | 3,095 |
| Alastair Garfield Chief Scientific Officer | Aug 13, 2026 | Sale(10b5-1 plan) | −2,007 | $116.11 | $233.03K | 8,051 |
| Alastair Garfield Chief Scientific Officer | Aug 13, 2026 | Sale(10b5-1 plan) | −800 | $119.17 | $95.34K | 2,295 |
| Alastair Garfield Chief Scientific Officer | Aug 13, 2026 | Sale(10b5-1 plan) | −1,556 | $117.08 | $182.18K | 6,495 |
| Joseph Shulman Chief Technical Officer | Aug 13, 2026 | Option exercise | +2,024 | $6.80 | $13.76K | 20,994 |
| Joseph Shulman Chief Technical Officer | Aug 13, 2026 | Sale(10b5-1 plan) | −5,079 | $119.75 | $608.21K | 15,915 |
| Jennifer Kayden Lee EVP, Head of North America | Aug 13, 2026 | Option exercise | +21,601 | $6.80 | $146.89K | 75,834 |
| Jennifer Kayden Lee EVP, Head of North America | Aug 13, 2026 | Option exercise | +35,000 | $24.29 | $850.15K | 54,233 |
| Jennifer Kayden Lee EVP, Head of North America | Aug 13, 2026 | Sale(10b5-1 plan) | −75,834 | $117.38 | $8.90M | 0 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Sale(10b5-1 plan) | −3,605 | $114.70 | $413.49K | 105,750 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Option exercise | +46,625 | $6.80 | $317.05K | 112,655 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Sale(10b5-1 plan) | −2,300 | $111.80 | $257.14K | 110,355 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Sale(10b5-1 plan) | −1,000 | $112.86 | $112.86K | 109,355 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Sale(10b5-1 plan) | −17,319 | $117.47 | $2.03M | 55,655 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Sale(10b5-1 plan) | −18,208 | $116.49 | $2.12M | 72,974 |
| Yann Mazabraud EVP, Head of International | Aug 12, 2026 | Sale(10b5-1 plan) | −14,568 | $115.43 | $1.68M | 91,182 |
| Alastair Garfield Chief Scientific Officer | Jul 1, 2026 | Tax withholding | −2,150 | $110.41 | $237.38K | 10,058 |
| Alastair Garfield Chief Scientific Officer | Jul 1, 2026 | Option exercise | +4,445 | – | – | 12,208 |
| Christophe Jean Director | Jun 23, 2026 | Option exercise | +4,712 | – | – | 11,712 |
| David W. J. McGirr Director | Jun 23, 2026 | Option exercise | +4,712 | – | – | 11,712 |
| Stuart A. Arbuckle Director | Jun 23, 2026 | Option exercise | +4,712 | – | – | 11,712 |
| Jennifer L. Good Director | Jun 23, 2026 | Option exercise | +4,712 | – | – | 11,712 |
| Lynn A. Tetrault Director | Jun 23, 2026 | Option exercise | +4,712 | – | – | 11,712 |
| Lynn A. Tetrault Director | Jun 22, 2026 | Option exercise | +37,000 | $28.27 | $1.05M | 44,000 |
| Lynn A. Tetrault Director | Jun 22, 2026 | Sale(10b5-1 plan) | −37,000 | $100.32 | $3.71M | 7,000 |
| Hunter C. Smith Chief Financial Officer | May 18, 2026 | Option exercise | +3,000 | $17.87 | $53.61K | 119,611 |
| Christopher Paul German Corporate Controller & CAO | May 15, 2026 | Option exercise | +1,687 | $56.69 | $95.64K | 1,888 |
| Christopher Paul German Corporate Controller & CAO | May 15, 2026 | Option exercise | +1,349 | $49.23 | $66.41K | 3,237 |
| Christopher Paul German Corporate Controller & CAO | May 15, 2026 | Sale | −4,643 | $92.21 | $428.13K | 0 |
| Christopher Paul German Corporate Controller & CAO | May 15, 2026 | Option exercise | +1,406 | $17.97 | $25.27K | 4,643 |
| Yann Mazabraud EVP, Head of International | Apr 1, 2026 | Option exercise | +12,875 | – | – | 66,030 |
| Edward T. Mathers Director | Mar 12, 2026 | Other | +4,199 | – | – | 14,168 |
| Christopher Paul German Corporate Controller & CAO | Mar 4, 2026 | Option exercise | +1,500 | $17.97 | $26.96K | 5,753 |
| Christopher Paul German Corporate Controller & CAO | Mar 4, 2026 | Sale | −5,614 | $89.56 | $502.79K | 160 |
| Edward T. Mathers Director | Mar 2, 2026 | Other | +4,198 | – | – | 9,969 |
| Hunter C. Smith Chief Financial Officer | Mar 2, 2026 | Option exercise | +6,099 | $6.80 | $41.47K | 116,611 |
| Christopher Paul German Corporate Controller & CAO | Mar 1, 2026 | Tax withholding | −342 | $94.94 | $32.47K | 4,253 |
| Christopher Paul German Corporate Controller & CAO | Mar 1, 2026 | Option exercise | +1,162 | – | – | 4,595 |
| Hunter C. Smith Chief Financial Officer | Feb 19, 2026 | Sale(10b5-1 plan) | −585 | $103.28 | $60.42K | 110,512 |
| Hunter C. Smith Chief Financial Officer | Feb 19, 2026 | Sale(10b5-1 plan) | −800 | $102.10 | $81.68K | 111,097 |
| Hunter C. Smith Chief Financial Officer | Feb 19, 2026 | Sale(10b5-1 plan) | −1,692 | $100.92 | $170.76K | 111,897 |
| Hunter C. Smith Chief Financial Officer | Feb 19, 2026 | Sale(10b5-1 plan) | −1,308 | $100.27 | $131.15K | 113,589 |
| Hunter C. Smith Chief Financial Officer | Feb 17, 2026 | Sale(10b5-1 plan) | −200 | $103.84 | $20.77K | 114,897 |
| Hunter C. Smith Chief Financial Officer | Feb 17, 2026 | Sale(10b5-1 plan) | −1,200 | $99.42 | $119.30K | 117,266 |
| Hunter C. Smith Chief Financial Officer | Feb 17, 2026 | Sale(10b5-1 plan) | −1,069 | $103.00 | $110.11K | 115,097 |
| Hunter C. Smith Chief Financial Officer | Feb 17, 2026 | Sale(10b5-1 plan) | −900 | $101.70 | $91.53K | 116,166 |
| Hunter C. Smith Chief Financial Officer | Feb 17, 2026 | Sale(10b5-1 plan) | −200 | $100.52 | $20.10K | 117,066 |
| Yann Mazabraud EVP, Head of International | Feb 14, 2026 | Option exercise | +10,000 | – | – | 53,155 |
| Hunter C. Smith Chief Financial Officer | Feb 12, 2026 | Sale(10b5-1 plan) | −292 | $96.26 | $28.11K | 119,766 |
| Hunter C. Smith Chief Financial Officer | Feb 12, 2026 | Sale(10b5-1 plan) | −400 | $97.67 | $39.07K | 119,366 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Short interest
Shares sold short and not yet bought back, as of Oct 30, 2026 (FINRA, reported twice a month)
Short % of float
17.14%
12M shares short
Days to cover
23.3
At 1M shares a day
Change since last report
+6.1%
From 11M shares
Short volume, 20 days
57.8%
Of volume reported to FINRA
Shares sold short, last 12 months
Short sale volume counts trades marked short on any given day, including market-maker hedging, so it runs far higher than the share of Rhythm Pharmaceuticals's stock actually held short. Settlement fails (shares not delivered on time) peaked at 17,169 shares on Oct 5, 2026 over the last 90 days.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| David P. Meeker Director, Officer | Sep 14, 2026 | 50,000 | $5.24M | Sep 14, 2026 | Exercise of Stock Options |
| Hunter C. Smith Officer | Aug 31, 2026 | 62,774 | $6.73M | Aug 31, 2026 | Exercise of Stock Options |
| Jennifer Kayden Lee Officer | Aug 13, 2026 | 75,834 | $8.92M | Aug 13, 2026 | Exercise of Stock Options |
| Joseph Shulman Officer | Aug 13, 2026 | 5,079 | $597.29K | Aug 13, 2026 | Exercise of Stock Options |
| Alastair Garfield Officer | Aug 13, 2026 | 7,763 | $912.93K | Aug 13, 2026 | Restricted Stock Units |
| Yann Mazabraud Officer | Aug 12, 2026 | 57,000 | $6.43M | Aug 12, 2026 | Exercise of Stock Options |
| Pamela J. Cramer Officer | Aug 11, 2026 | 11,406 | $1.32M | Aug 11, 2026 | Exercise of Stock Options |
| Pamela J. Cramer Officer | Aug 10, 2026 | 3,520 | $407.02K | Aug 10, 2026 | Exercise of Stock Options |
| Lynn A. Tetrault Director | Jun 22, 2026 | 37,000 | $3.58M | Jun 22, 2026 | Exercise of Stock Options |
| Camille L. Bedrosian Director | Mar 4, 2026 | 64,540 | $5.85M | Mar 4, 2026 | Exercise of options under a registered plan |
| Camille L. Bedrosian Director | Mar 3, 2026 | 35,460 | $3.21M | Mar 3, 2026 | Exercise of options under a registered plan |
| Hunter C. Smith Officer | Feb 5, 2026 | 18,406 | $1.99M | Feb 5, 2026 | Restricted Stock Units |
| Hunter C. Smith Officer | Feb 4, 2026 | 3,247 | $351.62K | Feb 4, 2026 | Restricted Stock Units |
| Pamela J. Cramer Officer | Dec 11, 2025 | 3,350 | $350.98K | Dec 11, 2025 | Exercise of Stock Options |
| Pamela J. Cramer Officer | Nov 20, 2025 | 3,350 | $345.55K | Nov 20, 2025 | Exercise of Stock Options |
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