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 ($138.3k 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 ≈ $7.95. Options: 4 managers hold calls ($495.3k notional), 3 hold puts ($232.1k).
Trends to Q4 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 |
| Q4 2025 | 130 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| 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 |
| Q4 2025 | 61 | 46 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2025 | $1.3m | $373.4k | 0.29 |
| Q2 2025 | $317.9k | $188.2k | 0.59 |
| Q3 2025 | $750.7k | $622.4k | 0.83 |
| Q4 2025 | $495.3k | $232.1k | 0.47 |
Biggest buyers
| Rubric Capital Management LP | Added | +2.4m |
| MILLENNIUM MANAGEMENT LLC | Added | +615.4k |
| MORGAN STANLEY | Added | +587.3k |
| Opaleye Management Inc. | New | +390.8k |
| Jefferies Financial Group Inc. | New | +298.2k |
| BlackRock, Inc. | Added | +295.6k |
| D. E. Shaw & Co., Inc. | Added | +208.6k |
| STEMPOINT CAPITAL LP | Added | +205.8k |
| Hennion & Walsh Asset Management, Inc. | Added | +199.5k |
| GOLDMAN SACHS GROUP INC | Added | +196.5k |
Biggest sellers
| PERCEPTIVE ADVISORS LLC | Reduced | -2.3m |
| J. Goldman & Co LP | Reduced | -1.5m |
| Prosight Management, LP | Reduced | -879.7k |
| ROYAL BANK OF CANADA | Reduced | -289.5k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -184.6k |
| Qube Research & Technologies Ltd | Sold out | -115.1k |
| JPMORGAN CHASE & CO | Reduced | -96.8k |
| 683 Capital Management, LLC | Reduced | -65.9k |
| CITADEL ADVISORS LLC | Reduced | -61.4k |
| Dynamic Technology Lab Private Ltd | Sold out | -45.4k |
Biggest calls
| Sender Co & Partners, Inc. | Added | $342.6k43.1k shares |
| GROUP ONE TRADING LLC | Reduced | $79.5k10.0k shares |
| SIMPLEX TRADING, LLC | Added | $73.1k9.2k shares |
| FNY Investment Advisers, LLC | Added | $069 shares |
Biggest puts
| JANE STREET GROUP, LLC | New | $214.7k27.0k shares |
| GROUP ONE TRADING LLC | Reduced | $9.5k1.2k shares |
| SIMPLEX TRADING, LLC | Reduced | $8.0k1.0k 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 Q4 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 |
|---|---|---|---|---|---|
| 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 |
| Q4 2025 | 0 | — | 2 | $611.4k | $611.4k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-10-21 | Giroux Richard CFO & COO | Sold plan | $212.9k24.0k shares |
| 2025-10-07 | Forbes Alexandria PRESIDENT & CEO, director | Sold plan | $398.5k47.5k 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, Q4 2025
| Manager | Shares | Change |
|---|---|---|
| Sanofi 31.24% of their portfolio | 12.2m $97.0m | Unchanged |
| PERCEPTIVE ADVISORS LLC 1.50% of their portfolio | 10.3m $82.1m | Reduced -2.3m |
| JOHNSON & JOHNSON 9.51% of their portfolio | 6.6m $52.8m | Unchanged |
| Rubric Capital Management LP 0.59% of their portfolio | 6.2m $49.1m | Added +2.4m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.05% of their portfolio | 4.0m $31.8m | Reduced -184.6k |
| Prosight Management, LP 5.27% of their portfolio | 3.2m $25.5m | Reduced -879.7k |
| MILLENNIUM MANAGEMENT LLC 0.02% of their portfolio | 3.2m $25.3m | Added +615.4k |
| BlackRock, Inc. 0.00% of their portfolio | 3.1m $24.4m | Added +295.6k |
| 683 Capital Management, LLC 1.69% of their portfolio | 2.6m $20.3m | Reduced -65.9k |
| MORGAN STANLEY 0.00% of their portfolio | 1.8m $14.5m | Added +587.3k |
| Knoll Capital Management, LLC 4.56% of their portfolio | 1.2m $9.9m | Unchanged |
| Erste Asset Management GmbH 0.05% of their portfolio | 789.7k $6.3m | Added +80.0k |
| STATE STREET CORP 0.00% of their portfolio | 729.4k $5.8m | Added +48.4k |
| 22NW, LP 1.96% of their portfolio | 586.5k $4.7m | Unchanged |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 573.8k $4.6m | Added +18.5k |
| Long Focus Capital Management, LLC 0.21% of their portfolio | 524.7k $4.2m | Unchanged |
| VANGUARD GROUP INC 0.00% of their portfolio | 494.8k $3.9m | Added +30.8k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 456.7k $3.6m | Added +196.5k |
| Opaleye Management Inc. 0.41% of their portfolio | 390.8k $3.1m | New |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 381.8k $3.0m | Added +208.6k |
| J. Goldman & Co LP 0.10% of their portfolio | 319.7k $2.5m | Reduced -1.5m |
| Hennion & Walsh Asset Management, Inc. 0.08% of their portfolio | 308.5k $2.5m | Added +199.5k |
| Woodline Partners LP 0.01% of their portfolio | 300.3k $2.4m | Added +100.0k |
| Jefferies Financial Group Inc. 0.02% of their portfolio | 298.2k $2.4m | New |
| STEMPOINT CAPITAL LP 0.39% of their portfolio | 287.7k $2.3m | Added +205.8k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 258.2k $2.1m | Reduced -12.7k |
| UBS Group AG 0.00% of their portfolio | 222.0k $1.8m | Added +140.4k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 208.5k $1.7m | Added +10.2k |
| Privium Fund Management B.V. 0.29% of their portfolio | 200.0k $1.6m | Added +37.0k |
| ROYCE & ASSOCIATES LP 0.01% of their portfolio | 176.1k $1.4m | New |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 143.4k $1.1m | Reduced -61.4k |
| Nuveen, LLC 0.00% of their portfolio | 131.1k $1.0m | Unchanged |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 130.6k $1.0m | Reduced -11.1k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 128.0k $1.0m | Added +119.1k |
| BLAIR WILLIAM & CO/IL 0.00% of their portfolio | 125.4k $996.9k | Reduced -7.1k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 111.4k $885.8k | Added +7.4k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 108.0k $858.7k | Added +230 |
| Bank of New York Mellon Corp 0.00% of their portfolio | 101.1k $803.7k | Reduced -4.7k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 98.2k $781.0k | Reduced -6.3k |
| BARCLAYS PLC 0.00% of their portfolio | 95.7k $761.1k | Added +11.7k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 95.7k $761.0k | Added +12.9k |
| PLATINUM INVESTMENT MANAGEMENT LTD 0.17% of their portfolio | 93.9k $746.7k | Reduced -33.6k |
| Invesco Ltd. 0.00% of their portfolio | 90.9k $722.5k | Added +21.4k |
| ExodusPoint Capital Management, LP 0.01% of their portfolio | 86.9k $691.1k | Added +44.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 76.9k $611.4k | Added +38.3k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.01% of their portfolio | 70.7k $562.4k | Added +1.5k |
| DAVENPORT & Co LLC 0.00% of their portfolio | 69.2k $550.1k | Added +14.0k |
| Trexquant Investment LP 0.00% of their portfolio | 67.5k $536.9k | New |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.01% of their portfolio | 66.4k $527.9k | Added +7.2k |
| Fort Sheridan Advisors LLC 0.07% of their portfolio | 65.6k $521.3k | Reduced -64 |
| Y-Intercept (Hong Kong) Ltd 0.01% of their portfolio | 65.6k $521.2k | New |
| Quantinno Capital Management LP 0.00% of their portfolio | 60.8k $483.0k | Added +3.5k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 57.2k $455.0k | New |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.00% of their portfolio | 56.2k $447.1k | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 56.2k $446.8k | Reduced -4.5k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 54.6k $434.0k | Unchanged |
| BROWN ADVISORY INC 0.00% of their portfolio | 50.0k $397.5k | Unchanged |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 49.8k $395.8k | Added +22.5k |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 47.6k $377.3k | Added +28.4k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 42.6k $339.0k | Unchanged |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 40.7k $323.7k | Added +7.4k |
| XTX Topco Ltd 0.01% of their portfolio | 38.0k $302.3k | Added +3.8k |
| Jump Financial, LLC 0.00% of their portfolio | 37.0k $294.1k | Reduced -33.6k |
| VARCOV Co. 0.10% of their portfolio | 32.9k $261.9k | First filing |
| LETKO, BROSSEAU & ASSOCIATES INC 0.00% of their portfolio | 32.0k $254.4k | Unchanged |
| Virtus Investment Advisers, LLC 0.06% of their portfolio | 29.8k $237.1k | New |
| AlphaCentric Advisors LLC 0.23% of their portfolio | 28.5k $226.5k | First filing |
| Engineers Gate Manager LP 0.00% of their portfolio | 26.8k $213.4k | New |
| CreativeOne Wealth, LLC 0.01% of their portfolio | 26.4k $210.1k | Reduced -5.2k |
| SkyView Investment Advisors, LLC 0.02% of their portfolio | 24.0k $191.0k | Unchanged |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 23.9k $190.4k | Reduced -96.8k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 22.8k $182.0k | Unchanged |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.00% of their portfolio | 22.6k $176.3k | New |
| FOX RUN MANAGEMENT, L.L.C. 0.03% of their portfolio | 22.5k $178.8k | Reduced -479 |
| SG Americas Securities, LLC 0.00% of their portfolio | 22.4k $178.0k | Reduced -7.6k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 21.0k $167.0k | Added +2.0k |
| Beacon Pointe Advisors, LLC 0.00% of their portfolio | 20.8k $165.1k | Unchanged |
| MetLife Investment Management, LLC 0.00% of their portfolio | 20.0k $159.3k | Reduced -4.2k |
| Voleon Capital Management LP 0.00% of their portfolio | 16.6k $131.9k | New |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 16.0k $127.3k | Unchanged |
| CITIGROUP INC 0.00% of their portfolio | 15.6k $123.6k | Added +2.1k |
| Creative Planning 0.00% of their portfolio | 15.4k $122.8k | Reduced -1.1k |
| CIBC Private Wealth Group LLC 0.00% of their portfolio | 15.0k $119.2k | Unchanged |
| Perigon Wealth Management, LLC 0.00% of their portfolio | 15.0k $119.2k | New |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 14.9k $118.4k | Reduced -577 |
| FMR LLC 0.00% of their portfolio | 13.8k $109.9k | Added +8.3k |
| China Universal Asset Management Co., Ltd. 0.01% of their portfolio | 13.1k $104.3k | Reduced -985 |
| Abel Hall, LLC 0.02% of their portfolio | 12.3k $97.7k | New |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.00% of their portfolio | 12.2k $97.3k | Unchanged |
| Hobbs Group Advisors, LLC 0.03% of their portfolio | 12.0k $95.0k | Reduced -2.3k |
| ProShare Advisors LLC 0.00% of their portfolio | 11.8k $93.7k | New |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 11.7k $92.7k | Unchanged |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 10.9k $87.0k | Reduced -289.5k |
| LEVIN CAPITAL STRATEGIES, L.P. 0.01% of their portfolio | 10.0k $79.5k | Reduced -15.0k |
| CWM, LLC 0.00% of their portfolio | 7.8k $62.0k | Reduced -67 |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 7.3k $57.7k | Unchanged |
| Rockefeller Capital Management L.P. 0.00% of their portfolio | 6.1k $48.7k | Added +630 |
| Legal & General Group Plc 0.00% of their portfolio | 4.3k $34.0k | Reduced -139 |
| State of Alaska, Department of Revenue 0.00% of their portfolio | 4.0k $32.0k | Unchanged |
| Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio | 3.9k $31.1k | Added +801 |