MEIRAGTX HLDGS PLC MGTX
COM · Common Stock · CUSIP G59665102
- SectorHealth care
- IndustryBiological Products, (No Diagnostic Substances)
- HeadquartersNew York, NY
- 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 ($59.5k this quarter). Holder counts are more reliable. Shares outstanding: 80.5m as of 2025-10-28, 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 ≈ $8.23. Options: 6 managers hold calls ($750.7k notional), 4 hold puts ($622.4k).
Trends to Q3 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 100 |
| Q4 2022 | 99 |
| Q1 2023 | 92 |
| Q2 2023 | 80 |
| Q3 2023 | 76 |
| Q4 2023 | 87 |
| Q1 2024 | 97 |
| Q2 2024 | 96 |
| Q3 2024 | 100 |
| Q4 2024 | 103 |
| Q1 2025 | 119 |
| Q2 2025 | 113 |
| Q3 2025 | 123 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q4 2023 | 44 | 29 |
| Q1 2024 | 48 | 38 |
| Q2 2024 | 48 | 43 |
| Q3 2024 | 46 | 36 |
| Q4 2024 | 56 | 36 |
| Q1 2025 | 65 | 37 |
| Q2 2025 | 52 | 61 |
| Q3 2025 | 53 | 52 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q4 2024 | $1.7m | $233.6k | 0.14 |
| Q1 2025 | $1.3m | $373.4k | 0.29 |
| Q2 2025 | $317.9k | $188.2k | 0.59 |
| Q3 2025 | $750.7k | $622.4k | 0.83 |
Biggest buyers
| MILLENNIUM MANAGEMENT LLC | Added | +1.8m |
| MORGAN STANLEY | Added | +787.6k |
| Woodline Partners LP | New | +200.3k |
| D. E. Shaw & Co., Inc. | New | +173.2k |
| GOLDMAN SACHS GROUP INC | Added | +113.7k |
| JANE STREET GROUP, LLC | New | +104.5k |
| JPMORGAN CHASE & CO | Added | +95.9k |
| STEMPOINT CAPITAL LP | New | +81.9k |
| AMH Equity Ltd | New | +80.0k |
| Jump Financial, LLC | New | +70.6k |
Biggest sellers
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -1.9m |
| Prosight Management, LP | Reduced | -497.9k |
| ROYAL BANK OF CANADA | Reduced | -307.4k |
| J. Goldman & Co LP | Reduced | -243.6k |
| ROYCE & ASSOCIATES LP | Sold out | -217.1k |
| DIMENSIONAL FUND ADVISORS LP | Sold out | -149.8k |
| Balyasny Asset Management L.P. | Sold out | -140.9k |
| READYSTATE ASSET MANAGEMENT LP | Sold out | -133.4k |
| HRT FINANCIAL LP | Sold out | -102.6k |
| BlackRock, Inc. | Reduced | -88.1k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | $383.5k46.6k shares |
| Sender Co & Partners, Inc. | New | $141.6k17.2k shares |
| MILLENNIUM MANAGEMENT LLC | New | $93.0k11.3k shares |
| GROUP ONE TRADING LLC | Added | $85.6k10.4k shares |
| SIMPLEX TRADING, LLC | Reduced | $47.0k5.8k shares |
| FNY Investment Advisers, LLC | New | $028 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | $370.4k45.0k shares |
| CITADEL ADVISORS LLC | Added | $140.7k17.1k shares |
| GROUP ONE TRADING LLC | Reduced | $91.4k11.1k shares |
| SIMPLEX TRADING, LLC | Reduced | $20.0k2.5k 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 |
|---|---|
| PERCEPTIVE ADVISORS LLC 13D · may seek influence -0.3 pts · filed 2026-04-24 | 12.6% |
| Rubric Capital Management LP 13G · institution +1.9 pts · filed 2026-08-14 | 9.8% |
Fell to 5% or below in the last year: Adage Capital Management, L.P. (4.9%, 2026-05-13), Prosight Management, LP (4.0%, 2026-02-13)
Insider purchases and sales in Q3 2025
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 2023 | 0 | — | 0 | — | — |
| Q1 2024 | 0 | — | 0 | — | — |
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 1 | $5.0m | 0 | — | — |
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 2 | $456.3k | $456.3k |
| Q2 2025 | 0 | — | 2 | $397.6k | $397.6k |
| Q3 2025 | 0 | — | 2 | $583.1k | $583.1k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-07-22 | Giroux Richard CFO & COO | Sold plan | $204.5k24.0k shares |
| 2025-07-08 | Forbes Alexandria PRESIDENT & CEO, director | Sold plan | $378.6k47.5k 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, Q3 2025
| Manager | Shares | Change |
|---|---|---|
| PERCEPTIVE ADVISORS LLC 3.00% of their portfolio | 12.6m $103.8m | Unchanged |
| Sanofi 38.56% of their portfolio | 12.2m $100.4m | Unchanged |
| JOHNSON & JOHNSON 10.85% of their portfolio | 6.6m $54.7m | Unchanged |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.05% of their portfolio | 4.2m $34.4m | Reduced -1.9m |
| Prosight Management, LP 8.08% of their portfolio | 4.1m $33.7m | Reduced -497.9k |
| Rubric Capital Management LP 0.41% of their portfolio | 3.7m $30.7m | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 2.8m $22.8m | Reduced -88.1k |
| 683 Capital Management, LLC 1.96% of their portfolio | 2.6m $21.6m | Reduced -65.0k |
| MILLENNIUM MANAGEMENT LLC 0.02% of their portfolio | 2.6m $21.1m | Added +1.8m |
| J. Goldman & Co LP 0.56% of their portfolio | 1.8m $14.8m | Reduced -243.6k |
| Knoll Capital Management, LLC 5.51% of their portfolio | 1.2m $10.3m | Unchanged |
| MORGAN STANLEY 0.00% of their portfolio | 1.2m $10.2m | Added +787.6k |
| Erste Asset Management GmbH 0.06% of their portfolio | 709.7k $5.9m | Reduced -80.0k |
| STATE STREET CORP 0.00% of their portfolio | 681.0k $5.6m | Reduced -1.2k |
| 22NW, LP 2.27% of their portfolio | 586.5k $4.8m | Unchanged |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 555.3k $4.6m | Reduced -2.3k |
| Long Focus Capital Management, LLC 0.25% of their portfolio | 524.7k $4.3m | Unchanged |
| VANGUARD GROUP INC 0.00% of their portfolio | 463.9k $3.8m | Added +43.3k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 300.3k $2.5m | Reduced -307.4k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 270.9k $2.2m | Reduced -3.0k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 260.2k $2.1m | Added +113.7k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 204.9k $1.7m | Added +3.3k |
| Woodline Partners LP 0.01% of their portfolio | 200.3k $1.6m | New |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 198.2k $1.6m | Reduced -68.5k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 173.2k $1.4m | New |
| Privium Fund Management B.V. 0.24% of their portfolio | 163.0k $1.3m | Unchanged |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 141.7k $1.2m | Reduced -80.7k |
| BLAIR WILLIAM & CO/IL 0.00% of their portfolio | 132.5k $1.1m | Unchanged |
| Nuveen, LLC 0.00% of their portfolio | 131.1k $1.1m | Reduced -8.0k |
| PLATINUM INVESTMENT MANAGEMENT LTD 0.07% of their portfolio | 127.5k $1.0m | Reduced -80.8k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 120.8k $994.1k | Added +95.9k |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 115.1k $946.9k | Added +33.8k |
| Hennion & Walsh Asset Management, Inc. 0.03% of their portfolio | 109.0k $896.9k | Added +44.9k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 107.8k $887.1k | Added +1.2k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 105.8k $870.7k | Reduced -2.4k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 104.5k $860.0k | New |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 104.1k $856.4k | Reduced -683 |
| BARCLAYS PLC 0.00% of their portfolio | 84.0k $691.3k | Reduced -24.1k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 82.8k $681.8k | Added +3.5k |
| STEMPOINT CAPITAL LP 0.14% of their portfolio | 81.9k $673.7k | New |
| UBS Group AG 0.00% of their portfolio | 81.6k $671.5k | Added +8.7k |
| AMH Equity Ltd 0.83% of their portfolio | 80.0k $658.4k | New |
| Jump Financial, LLC 0.01% of their portfolio | 70.6k $581.0k | New |
| Invesco Ltd. 0.00% of their portfolio | 69.5k $572.0k | Added +25.3k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.01% of their portfolio | 69.2k $569.9k | Added +34.1k |
| Fort Sheridan Advisors LLC 0.07% of their portfolio | 65.6k $540.2k | Reduced -2.8k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 60.7k $499.4k | Reduced -3.0k |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.01% of their portfolio | 59.2k $487.2k | Added +14.7k |
| Quantinno Capital Management LP 0.00% of their portfolio | 57.2k $471.0k | Added +8.3k |
| DAVENPORT & Co LLC 0.00% of their portfolio | 55.2k $454.3k | Unchanged |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 54.6k $449.3k | Unchanged |
| BROWN ADVISORY INC 0.00% of their portfolio | 50.0k $411.5k | Unchanged |
| Dynamic Technology Lab Private Ltd 0.06% of their portfolio | 45.4k $374.0k | New |
| ExodusPoint Capital Management, LP 0.00% of their portfolio | 43.0k $353.7k | New |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 42.6k $351.0k | Added +15.8k |
| Sender Co & Partners, Inc. 0.13% of their portfolio | 40.7k $334.7k | Reduced -20.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 38.6k $317.9k | Reduced -49.9k |
| XTX Topco Ltd 0.01% of their portfolio | 34.3k $282.0k | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 33.3k $274.2k | Added +4.2k |
| LETKO, BROSSEAU & ASSOCIATES INC 0.00% of their portfolio | 32.0k $263.4k | Reduced -13.3k |
| CreativeOne Wealth, LLC 0.01% of their portfolio | 31.6k $259.9k | Reduced -5.0k |
| SG Americas Securities, LLC 0.00% of their portfolio | 30.0k $247.0k | New |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 27.3k $224.7k | Added +4.4k |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 26.4k $217.3k | Reduced -6.1k |
| LEVIN CAPITAL STRATEGIES, L.P. 0.02% of their portfolio | 25.0k $205.8k | Unchanged |
| GSA CAPITAL PARTNERS LLP 0.02% of their portfolio | 24.7k $203.0k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 24.2k $199.1k | Reduced -6.6k |
| SkyView Investment Advisors, LLC 0.03% of their portfolio | 24.0k $198.0k | Unchanged |
| FOX RUN MANAGEMENT, L.L.C. 0.03% of their portfolio | 23.0k $189.1k | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 22.8k $188.0k | Unchanged |
| Beacon Pointe Advisors, LLC 0.00% of their portfolio | 20.8k $170.9k | New |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 19.1k $158.1k | Added +7.2k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 19.0k $156.7k | Reduced -3.8k |
| Creative Planning 0.00% of their portfolio | 16.6k $136.5k | Added +3.8k |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 16.0k $131.8k | Reduced -558 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 15.5k $127.4k | Reduced -1.3k |
| CIBC Private Wealth Group LLC 0.00% of their portfolio | 15.0k $123.5k | Unchanged |
| Hobbs Group Advisors, LLC 0.04% of their portfolio | 14.2k $117.0k | Unchanged |
| China Universal Asset Management Co., Ltd. 0.01% of their portfolio | 14.1k $116.1k | Reduced -2.0k |
| CITIGROUP INC 0.00% of their portfolio | 13.4k $110.4k | Reduced -4.9k |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.00% of their portfolio | 12.2k $100.7k | Unchanged |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 11.7k $96.0k | Unchanged |
| Family Manage LLC 0.01% of their portfolio | 10.0k $82.3k | Unchanged |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 8.9k $73.6k | Added +4.1k |
| CWM, LLC 0.00% of their portfolio | 7.8k $65.0k | Reduced -584 |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 7.3k $59.8k | Unchanged |
| FNY Investment Advisers, LLC 0.02% of their portfolio | 6.4k $52.0k | Reduced -2.9k |
| FMR LLC 0.00% of their portfolio | 5.5k $45.5k | Added +61 |
| Rockefeller Capital Management L.P. 0.00% of their portfolio | 5.5k $45.3k | New |
| Legal & General Group Plc 0.00% of their portfolio | 4.4k $36.3k | Unchanged |
| Arax Advisory Partners 0.00% of their portfolio | 4.3k $35.2k | New |
| State of Alaska, Department of Revenue 0.00% of their portfolio | 4.0k $33.0k | New |
| Ameritas Investment Partners, Inc. 0.00% of their portfolio | 3.5k $28.6k | Reduced -1.4k |
| Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio | 3.1k $25.6k | Added +6 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 2.6k $21.4k | New |
| Versant Capital Management, Inc 0.00% of their portfolio | 2.3k $18.7k | Added +18 |
| GF FUND MANAGEMENT CO. LTD. 0.00% of their portfolio | 1.7k $14.2k | Reduced -270 |
| AMALGAMATED BANK 0.00% of their portfolio | 1.6k $13.0k | Unchanged |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 1.5k $12.4k | Reduced -7.3k |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 1.3k $10.4k | Reduced -572 |