CULLINAN THERAPEUTICS INC CGEM
COM · Common Stock · CUSIP 230031106 · ISIN US2300311063
- SectorHealth care
- IndustryBiological Products, (No Diagnostic Substances)
- HeadquartersCambridge, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($144.8k this quarter). Holder counts are more reliable. Shares outstanding: 64.4m as of 2026-07-31, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $18.21. Options: 5 managers hold calls ($3.4m notional), 5 hold puts ($2.8m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 100 |
| Q4 2022 | 98 |
| Q1 2023 | 104 |
| Q2 2023 | 107 |
| Q3 2023 | 107 |
| Q4 2023 | 114 |
| Q1 2024 | 114 |
| Q2 2024 | 136 |
| Q3 2024 | 138 |
| Q4 2024 | 148 |
| Q1 2025 | 150 |
| Q2 2025 | 145 |
| Q3 2025 | 145 |
| Q4 2025 | 153 |
| Q1 2026 | 174 |
| Q2 2026 | 184 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 83 | 45 |
| Q4 2024 | 76 | 56 |
| Q1 2025 | 67 | 73 |
| Q2 2025 | 70 | 68 |
| Q3 2025 | 83 | 63 |
| Q4 2025 | 90 | 58 |
| Q1 2026 | 95 | 59 |
| Q2 2026 | 112 | 67 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $175.3k | $279.5k | 1.59 |
| Q4 2025 | $3.9m | $724.5k | 0.19 |
| Q1 2026 | $2.9m | $977.6k | 0.34 |
| Q2 2026 | $3.4m | $2.8m | 0.83 |
Biggest buyers
| MPM BIOIMPACT LLC | Added | +2.1m |
| PRICE T ROWE ASSOCIATES INC /MD/ | Added | +1.8m |
| STATE STREET CORP | Added | +1.1m |
| BlackRock, Inc. | Added | +782.8k |
| BOONE CAPITAL MANAGEMENT LLC | New | +704.4k |
| Siren, L.L.C. | Added | +700.0k |
| RTW INVESTMENTS, LP | Added | +658.4k |
| GOLDMAN SACHS GROUP INC | Added | +546.1k |
| PERCEPTIVE ADVISORS LLC | New | +426.5k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | New | +238.0k |
Biggest sellers
| Nextech Invest Ltd. | Sold out | -1.1m |
| MARSHALL WACE, LLP | Reduced | -983.5k |
| Point72 Asset Management, L.P. | Reduced | -830.4k |
| DEERFIELD MANAGEMENT COMPANY, L.P. | Sold out | -386.2k |
| Blue Owl Capital Holdings LP | Reduced | -370.0k |
| Soleus Capital Management, L.P. | Reduced | -360.2k |
| Nuveen, LLC | Reduced | -333.8k |
| TWO SIGMA INVESTMENTS, LP | Reduced | -249.5k |
| ORBIMED ADVISORS LLC | Sold out | -243.0k |
| SCHRODER INVESTMENT MANAGEMENT GROUP | Sold out | -173.7k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $1.6m86.6k shares |
| CITADEL ADVISORS LLC | Added | $919.6k50.5k shares |
| JANE STREET GROUP, LLC | New | $508.1k27.9k shares |
| MILLENNIUM MANAGEMENT LLC | Unchanged | $364.2k20.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $16.4k900 shares |
Biggest puts
| CITADEL ADVISORS LLC | New | $1.2m65.2k shares |
| JANE STREET GROUP, LLC | New | $668.3k36.7k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $655.6k36.0k shares |
| GROUP ONE TRADING LLC | New | $233.1k12.8k shares |
| SIMPLEX TRADING, LLC | Reduced | $67.4k3.7k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| BIOTECHNOLOGY VALUE FUND L P 13G · passive investor no change · filed 2026-08-14 | 10.0% |
| Lynx1 Capital Management LP 13G · passive investor -4.7 pts · filed 2025-11-14 | 9.8% |
| PRICE T ROWE ASSOCIATES INC /MD/ 13G · institution new · filed 2026-08-14 | 6.2% |
| STATE STREET CORP 13G · institution new · filed 2026-08-07 | 6.0% |
| Kynam Capital Management, LP 13G · institution new · filed 2026-03-04 | 5.3% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-26), CITADEL ADVISORS LLC (3.4%, 2025-11-14), Flynn James E (5.0%, 2025-11-13)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 4 | $414.6k | $125.1k |
| Q1 2025 | 0 | — | 4 | $230.7k | $50.0k |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 4 | $306.9k | $101.1k |
| Q1 2026 | 0 | — | 5 | $1.1m | $338.7k |
| Q2 2026 | 0 | — | 1 | $117.0k | $117.0k |
| Q3 2026 | 0 | — | 1 | $922.9k | $922.9k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-08 | Michaelson Jennifer Chief Scientific Officer | Sold plan | $172.6k8.0k shares |
| 2026-08-13 | Michaelson Jennifer Chief Scientific Officer | Sold plan | $607.8k30.0k shares |
| 2026-07-06 | Michaelson Jennifer Chief Scientific Officer | Sold plan | $142.6k8.0k shares |
| 2026-05-05 | Michaelson Jennifer Chief Scientific Officer | Sold plan | $117.0k8.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| MPM BIOIMPACT LLC 10.81% of their portfolio | 9.7m $177.2m | Added +2.1m |
| Lynx1 Capital Management LP 18.86% of their portfolio | 9.0m $163.2m | Unchanged |
| BVF INC/IL 2.68% of their portfolio | 5.8m $104.7m | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 5.2m $95.3m | Added +782.8k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 3.8m $69.7m | Added +1.8m |
| STATE STREET CORP 0.00% of their portfolio | 3.7m $66.8m | Added +1.1m |
| Kynam Capital Management, LP 3.13% of their portfolio | 3.1m $56.7m | Unchanged |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 2.6m $47.6m | Added +131.0k |
| RTW INVESTMENTS, LP 0.37% of their portfolio | 2.4m $43.1m | Added +658.4k |
| Siren, L.L.C. 0.70% of their portfolio | 1.9m $34.5m | Added +700.0k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.5m $28.2m | Added +179.0k |
| Blue Owl Capital Holdings LP 4.26% of their portfolio | 1.5m $28.0m | Reduced -370.0k |
| Venrock Adviser, LLC 0.76% of their portfolio | 1.4m $25.1m | Unchanged |
| BOOTHBAY FUND MANAGEMENT, LLC 0.37% of their portfolio | 1.1m $19.7m | Reduced -30.2k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 1.0m $19.1m | Added +140.7k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 1.0m $18.2m | Added +546.1k |
| Affinity Asset Advisors, LLC 0.78% of their portfolio | 875.8k $15.9m | Added +94.5k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 738.7k $13.5m | Added +186.2k |
| BOONE CAPITAL MANAGEMENT LLC 3.00% of their portfolio | 704.4k $12.8m | New |
| Elmind Capital, LP 3.16% of their portfolio | 690.0k $12.6m | Added +160.0k |
| MORGAN STANLEY 0.00% of their portfolio | 629.0k $11.5m | Added +39.6k |
| TWIN FOCUS CAPITAL PARTNERS, LLC 1.10% of their portfolio | 595.5k $10.8m | Unchanged |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 581.3k $10.6m | Added +220.5k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 571.1k $10.4m | Added +121.8k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 510.3k $9.3m | Reduced -6.4k |
| Nuveen, LLC 0.00% of their portfolio | 471.9k $8.6m | Reduced -333.8k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 464.0k $8.5m | Added +31.1k |
| PERCEPTIVE ADVISORS LLC 0.12% of their portfolio | 426.5k $7.8m | New |
| TCG Crossover Management, LLC 0.18% of their portfolio | 406.8k $7.4m | Unchanged |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 397.5k $7.2m | Added +144.7k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 382.8k $7.0m | Added +14.9k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 363.1k $6.6m | Added +20.3k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 346.2k $6.3m | Reduced -350 |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 326.8k $6.0m | Added +2.7k |
| GREAT POINT PARTNERS LLC 1.29% of their portfolio | 300.0k $5.5m | Unchanged |
| Connor, Clark & Lunn Investment Management Ltd. 0.01% of their portfolio | 292.5k $5.3m | Added +3.4k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 282.6k $5.2m | Reduced -14.6k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 272.6k $5.0m | Reduced -249.5k |
| Bleichroeder LP 0.81% of their portfolio | 250.0k $4.6m | Added +150.0k |
| UBS Group AG 0.00% of their portfolio | 248.6k $4.5m | Added +46.2k |
| FMR LLC 0.00% of their portfolio | 240.1k $4.4m | Added +232.9k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.01% of their portfolio | 238.0k $4.3m | New |
| Susquehanna Portfolio Strategies, LLC 0.07% of their portfolio | 233.8k $4.3m | Unchanged |
| PFM Health Sciences, LP 0.30% of their portfolio | 192.4k $3.5m | Reduced -35.0k |
| MOORE CAPITAL MANAGEMENT, LP 0.08% of their portfolio | 189.9k $3.5m | Added +84.0k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 171.0k $3.1m | Added +27.3k |
| Squarepoint Ops LLC 0.01% of their portfolio | 168.1k $3.1m | New |
| PRUDENTIAL FINANCIAL INC 0.00% of their portfolio | 167.6k $3.1m | Added +18.1k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 164.7k $3.0m | Added +15.1k |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 156.3k $2.8m | Added +12.2k |
| Engineers Gate Manager LP 0.04% of their portfolio | 153.1k $2.8m | Added +86.8k |
| Trexquant Investment LP 0.02% of their portfolio | 152.2k $2.8m | Reduced -16.3k |
| BARCLAYS PLC 0.00% of their portfolio | 143.9k $2.6m | Added +3.6k |
| Invesco Ltd. 0.00% of their portfolio | 143.6k $2.6m | Reduced -100.6k |
| Jump Financial, LLC 0.02% of their portfolio | 138.7k $2.5m | Reduced -55.1k |
| CITIGROUP INC 0.00% of their portfolio | 124.4k $2.3m | Reduced -19.7k |
| Assenagon Asset Management S.A. 0.00% of their portfolio | 123.4k $2.2m | Reduced -15.3k |
| Quantinno Capital Management LP 0.00% of their portfolio | 109.9k $2.0m | Added +37.6k |
| Creative Planning 0.00% of their portfolio | 86.5k $1.6m | Added +26.5k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 84.2k $1.5m | Added +16.5k |
| Y-Intercept (Hong Kong) Ltd 0.03% of their portfolio | 80.6k $1.5m | Reduced -14.8k |
| TD Asset Management Inc 0.00% of their portfolio | 80.6k $1.5m | Reduced -33.8k |
| Apis Capital Advisors, LLC 0.14% of their portfolio | 80.0k $1.5m | Added +20.0k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 78.9k $1.4m | Added +11.4k |
| XTX Topco Ltd 0.02% of their portfolio | 77.0k $1.4m | Added +50.6k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 76.7k $1.4m | Added +1.4k |
| Swiss National Bank 0.00% of their portfolio | 76.0k $1.4m | Added +17.7k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 75.2k $1.1m | Added +27.6k |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 75.0k $1.4m | Reduced -830.4k |
| Mariner, LLC 0.00% of their portfolio | 74.3k $1.4m | Added +11.6k |
| Knott David M Jr 0.67% of their portfolio | 69.2k $1.3m | Added +45.0k |
| Rafferty Asset Management, LLC 0.00% of their portfolio | 66.1k $1.2m | Reduced -3.4k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 66.1k $1.2m | Reduced -983.5k |
| Longaeva Partners L.P. 0.03% of their portfolio | 64.8k $1.2m | Reduced -118.9k |
| Tidal Investments LLC 0.00% of their portfolio | 62.8k $1.1m | Added +405 |
| Tema ETFs LLC 0.04% of their portfolio | 62.8k $1.1m | First filing |
| MARTINGALE ASSET MANAGEMENT L P 0.03% of their portfolio | 61.9k $1.1m | New |
| Corient Private Wealth LP 0.00% of their portfolio | 54.9k $999.3k | Added +27.0k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.02% of their portfolio | 53.0k $965.3k | Added +1.5k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 51.3k $933.4k | Added +30.3k |
| Soleus Capital Management, L.P. 0.03% of their portfolio | 50.0k $910.5k | Reduced -360.2k |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 42.3k $771.1k | New |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 40.3k $733.0k | Added +9.9k |
| ALGERT GLOBAL LLC 0.01% of their portfolio | 36.9k $671.1k | Reduced -72.9k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 36.8k $669.7k | Added +9.7k |
| Fisher Asset Management, LLC 0.00% of their portfolio | 36.0k $655.5k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 35.7k $650.9k | Added +4.9k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 35.5k $648.7k | Added +5.4k |
| IEQ CAPITAL, LLC 0.00% of their portfolio | 33.7k $614.0k | Added +6.0k |
| PROFUND ADVISORS LLC 0.02% of their portfolio | 33.4k $608.3k | Added +2.2k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 32.1k $585.2k | Added +12.1k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.00% of their portfolio | 31.7k $577.5k | New |
| Leonteq Securities AG 0.03% of their portfolio | 30.0k $546.3k | Added +20.0k |
| Verdad Advisers, LP 0.51% of their portfolio | 29.0k $527.9k | Added +16.4k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 28.6k $520.5k | Added +24.3k |
| ExodusPoint Capital Management, LP 0.00% of their portfolio | 28.5k $519.7k | New |
| OPTIMIZE FINANCIAL INC. 0.18% of their portfolio | 28.1k $511.0k | Reduced -97 |
| Sound Capital Solutions LLC 0.12% of their portfolio | 28.1k $511.0k | First filing |
| Legal & General Group Plc 0.00% of their portfolio | 27.5k $500.4k | Added +8.8k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 26.1k $475.1k | Reduced -21.3k |