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 ($830.9k this quarter). Holder counts are more reliable. Shares outstanding: 96.0m as of 2026-08-11, 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 ≈ $13.50. Options: 4 managers hold calls ($1.8m notional), 1 hold puts ($16.2k).
Trends to Q2 2026
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 |
| Q1 2026 | 133 |
| Q2 2026 | 157 |
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 | 46 | 36 |
| Q4 2024 | 56 | 36 |
| Q1 2025 | 65 | 37 |
| Q2 2025 | 52 | 61 |
| Q3 2025 | 53 | 52 |
| Q4 2025 | 61 | 46 |
| Q1 2026 | 65 | 55 |
| Q2 2026 | 119 | 34 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $750.7k | $622.4k | 0.83 |
| Q4 2025 | $495.3k | $232.1k | 0.47 |
| Q1 2026 | $251.1k | $417.4k | 1.66 |
| Q2 2026 | $1.8m | $16.2k | 0.01 |
Biggest buyers
| Rubric Capital Management LP | Added | +2.1m |
| BlackRock, Inc. | Added | +1.6m |
| Opaleye Management Inc. | Added | +1.4m |
| Woodline Partners LP | Added | +1.2m |
| JACOBS LEVY EQUITY MANAGEMENT, INC | Added | +1.0m |
| HEIGHTS CAPITAL MANAGEMENT, INC | New | +850.0k |
| STATE STREET CORP | Added | +639.8k |
| Long Focus Capital Management, LLC | Added | +555.6k |
| CITADEL ADVISORS LLC | Added | +534.5k |
| Nuveen, LLC | Added | +507.0k |
Biggest sellers
| Prosight Management, LP | Reduced | -2.5m |
| Logos Global Management LP | Sold out | -700.0k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -493.9k |
| MORGAN STANLEY | Reduced | -277.2k |
| Jefferies Financial Group Inc. | Sold out | -167.5k |
| 683 Capital Management, LLC | Reduced | -150.0k |
| UBS Group AG | Reduced | -118.6k |
| GOLDMAN SACHS GROUP INC | Reduced | -114.0k |
| JANE STREET GROUP, LLC | Sold out | -105.9k |
| BNP PARIBAS FINANCIAL MARKETS | Reduced | -99.6k |
Biggest calls
| J. Goldman & Co LP | New | $1.1m82.8k shares |
| SIMPLEX TRADING, LLC | Added | $672.8k49.8k shares |
| DIADEMA PARTNERS LP | New | $6.8k500 shares |
| Persistent Asset Partners Ltd | New | $6902 shares |
Biggest puts
| SIMPLEX TRADING, LLC | Added | $16.2k1.2k 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 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 | — | 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 |
| Q1 2026 | 0 | — | 1 | $459.4k | $459.4k |
| Q2 2026 | 0 | — | 3 | $1.4m | $1.4m |
| Q3 2026 | 0 | — | 3 | $2.0m | $2.0m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-08-18 | Forbes Alexandria PRESIDENT & CEO, director | Sold plan | $859.3k62.0k shares |
| 2026-07-21 | Giroux Richard CFO & COO | Sold plan | $700.6k56.0k shares |
| 2026-07-07 | Naylor Stuart CHIEF SCI OFCR, OPHTHALMOLOGY | Sold plan | $409.5k27.7k shares |
| 2026-05-19 | Forbes Alexandria PRESIDENT & CEO, director | Sold plan | $568.5k62.0k shares |
| 2026-04-21 | Giroux Richard CFO & COO | Sold plan | $572.3k56.0k shares |
| 2026-04-07 | Naylor Stuart CHIEF DEV. OFFICER | Sold plan | $258.9k27.7k 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 |
|---|---|---|
| Sanofi 30.86% of their portfolio | 12.2m $164.8m | Unchanged |
| PERCEPTIVE ADVISORS LLC 2.26% of their portfolio | 10.8m $145.7m | Added +460.6k |
| Rubric Capital Management LP 1.13% of their portfolio | 9.1m $122.9m | Added +2.1m |
| JOHNSON & JOHNSON 11.23% of their portfolio | 6.6m $89.7m | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 4.8m $64.3m | Added +1.6m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.08% of their portfolio | 4.4m $59.4m | Added +400.0k |
| Opaleye Management Inc. 4.34% of their portfolio | 3.5m $48.0m | Added +1.4m |
| MILLENNIUM MANAGEMENT LLC 0.03% of their portfolio | 3.0m $40.1m | Reduced -493.9k |
| 683 Capital Management, LLC 2.86% of their portfolio | 2.3m $31.1m | Reduced -150.0k |
| Woodline Partners LP 0.06% of their portfolio | 1.5m $20.3m | Added +1.2m |
| STATE STREET CORP 0.00% of their portfolio | 1.4m $18.8m | Added +639.8k |
| MORGAN STANLEY 0.00% of their portfolio | 1.3m $17.7m | Reduced -277.2k |
| Knoll Capital Management, LLC 9.42% of their portfolio | 1.2m $16.9m | Unchanged |
| KENNEDY CAPITAL MANAGEMENT LLC 0.26% of their portfolio | 1.1m $14.9m | Added +247.0k |
| Long Focus Capital Management, LLC 0.60% of their portfolio | 1.1m $14.6m | Added +555.6k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.05% of their portfolio | 1.0m $13.7m | Added +1.0m |
| D. E. Shaw & Co., Inc. 0.01% of their portfolio | 852.9k $11.5m | Added +427.6k |
| HEIGHTS CAPITAL MANAGEMENT, INC 2.65% of their portfolio | 850.0k $11.5m | New |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 849.1k $11.5m | Added +264.2k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 723.6k $9.8m | Added +326.3k |
| Erste Asset Management GmbH 0.07% of their portfolio | 691.2k $8.7m | Reduced -28.5k |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 650.5k $8.8m | Added +534.5k |
| Nuveen, LLC 0.00% of their portfolio | 639.5k $8.6m | Added +507.0k |
| J. Goldman & Co LP 0.29% of their portfolio | 602.0k $8.1m | Added +395.8k |
| Jupiter Topco LLC 0.00% of their portfolio | 475.8k $6.4m | First filing |
| PFM Health Sciences, LP 0.53% of their portfolio | 455.3k $6.2m | New |
| Hennion & Walsh Asset Management, Inc. 0.16% of their portfolio | 422.0k $5.7m | Added +67.2k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 409.9k $5.5m | Added +138.0k |
| PANAGORA ASSET MANAGEMENT INC 0.01% of their portfolio | 350.2k $4.7m | New |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 327.4k $4.4m | Reduced -114.0k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 289.7k $3.9m | Added +44.8k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 205.2k $2.6m | Added +180.9k |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 202.4k $2.7m | Added +131.4k |
| Ghisallo Capital Management LLC 0.05% of their portfolio | 200.0k $2.7m | New |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 196.6k $2.7m | Added +85.6k |
| Privium Fund Management B.V. 0.49% of their portfolio | 196.1k $2.6m | Reduced -16.0k |
| UBS Group AG 0.00% of their portfolio | 184.6k $2.5m | Reduced -118.6k |
| Squarepoint Ops LLC 0.00% of their portfolio | 162.4k $2.2m | Added +143.8k |
| Y-Intercept (Hong Kong) Ltd 0.04% of their portfolio | 148.1k $2.0m | New |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 147.3k $2.0m | Added +50.2k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 142.9k $1.9m | Added +16.6k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 142.4k $1.9m | Added +42.2k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 138.4k $1.9m | Added +38.3k |
| BLAIR WILLIAM & CO/IL 0.00% of their portfolio | 125.5k $1.7m | Added +56 |
| Voleon Capital Management LP 0.03% of their portfolio | 117.8k $1.6m | Added +95.4k |
| Swiss National Bank 0.00% of their portfolio | 111.4k $1.5m | New |
| BARCLAYS PLC 0.00% of their portfolio | 99.0k $1.3m | Added +60.8k |
| Invesco Ltd. 0.00% of their portfolio | 94.5k $1.3m | Added +105 |
| ALPS ADVISORS INC 0.01% of their portfolio | 93.2k $1.3m | New |
| Prosight Management, LP 0.21% of their portfolio | 90.0k $1.2m | Reduced -2.5m |
| Aquatic Capital Management LLC 0.04% of their portfolio | 87.1k $1.2m | Added +86.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 86.8k $1.2m | Added +31.1k |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.01% of their portfolio | 77.7k $1.0m | Added +9.5k |
| DAVENPORT & Co LLC 0.00% of their portfolio | 72.4k $977.7k | Added +3.2k |
| Engineers Gate Manager LP 0.01% of their portfolio | 69.1k $933.4k | Added +42.3k |
| Fort Sheridan Advisors LLC 0.10% of their portfolio | 66.4k $897.6k | Reduced -419 |
| Quantinno Capital Management LP 0.00% of their portfolio | 66.1k $893.5k | Added +9.7k |
| Trexquant Investment LP 0.01% of their portfolio | 65.4k $883.5k | Reduced -32.2k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 64.4k $869.6k | New |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 61.1k $825.1k | New |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 60.5k $818.0k | Added +58.1k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 60.5k $817.2k | Added +6.6k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 59.6k $804.8k | Added +29.4k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 54.7k $473.6k | Added +100 |
| AlphaCentric Advisors LLC 0.62% of their portfolio | 54.5k $735.9k | Added +775 |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 53.9k $728.3k | Added +37.3k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 50.2k $677.7k | Added +16.5k |
| BROWN ADVISORY INC 0.00% of their portfolio | 50.0k $675.5k | Unchanged |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 49.4k $668.0k | Added +17.9k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 49.2k $664.7k | Added +38.9k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 48.5k $654.9k | Added +11.6k |
| MARTINGALE ASSET MANAGEMENT L P 0.02% of their portfolio | 47.9k $646.5k | New |
| SEI INVESTMENTS CO 0.00% of their portfolio | 47.6k $643.1k | Reduced -52.0k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 40.3k $545.0k | New |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 40.2k $543.0k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 35.3k $476.6k | Added +12.6k |
| EntryPoint Capital, LLC 0.11% of their portfolio | 34.5k $466.2k | Added +2.6k |
| Virtus Investment Advisers, LLC 0.11% of their portfolio | 34.1k $460.9k | Added +3.5k |
| Legal & General Group Plc 0.00% of their portfolio | 32.8k $442.5k | Added +29.0k |
| CITIGROUP INC 0.00% of their portfolio | 32.7k $442.2k | Added +27.4k |
| LETKO, BROSSEAU & ASSOCIATES INC 0.01% of their portfolio | 32.0k $432.3k | Unchanged |
| AXQ CAPITAL, LP 0.05% of their portfolio | 31.2k $421.4k | New |
| PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO 0.00% of their portfolio | 30.7k $414.8k | New |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 28.9k $379.1k | Reduced -10.9k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 28.8k $388.7k | New |
| XTX Topco Ltd 0.00% of their portfolio | 28.0k $378.4k | Reduced -15.3k |
| PRUDENTIAL FINANCIAL INC 0.00% of their portfolio | 28.0k $378.2k | New |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 27.7k $374.0k | Added +6.2k |
| Beacon Pointe Advisors, LLC 0.00% of their portfolio | 26.8k $361.6k | Unchanged |
| CreativeOne Wealth, LLC 0.01% of their portfolio | 26.4k $357.0k | Unchanged |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.00% of their portfolio | 24.5k $331.4k | Added +2.5k |
| DIVERSIFIED TRUST CO 0.01% of their portfolio | 23.9k $323.2k | New |
| IEQ CAPITAL, LLC 0.00% of their portfolio | 22.3k $301.7k | New |
| STRS OHIO 0.00% of their portfolio | 22.2k $299.9k | Added +19.4k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 21.1k $284.6k | Added +13.8k |
| Creative Planning 0.00% of their portfolio | 20.5k $276.4k | Added +5.0k |
| CIBC Bancorp USA Inc. 0.00% of their portfolio | 18.3k $247.5k | Added +1.0k |
| State of New Jersey Common Pension Fund D 0.00% of their portfolio | 18.0k $242.6k | New |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 17.7k $239.6k | Added +6.1k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 17.0k $230.1k | Added +3.8k |