GENERATION BIO CO
COM · Common Stock · CUSIP 37148K100
* 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. Holder counts are more reliable. Implied quarter-end price ≈ $5.50. Options: 3 managers hold calls ($29.1k notional), 3 hold puts ($33.7k).
Trends to Q2 2023
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 116 |
| Q4 2022 | 100 |
| Q1 2023 | 86 |
| Q2 2023 | 82 |
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 2022 | 48 | 55 |
| Q1 2023 | 38 | 53 |
| Q2 2023 | 39 | 39 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2022 | $90.0k | $0 | 0.00 |
| Q4 2022 | $66.8k | $3.9k | 0.06 |
| Q1 2023 | $138.0k | $12.9k | 0.09 |
| Q2 2023 | $29.1k | $33.7k | 1.16 |
Biggest buyers
| JPMORGAN CHASE & CO | Added | +437.5k |
| T. Rowe Price Investment Management, Inc. | Added | +130.5k |
| DIMENSIONAL FUND ADVISORS LP | Added | +99.7k |
| BlackRock Inc. | Added | +90.6k |
| EcoR1 Capital, LLC | Added | +90.3k |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +70.9k |
| WELLINGTON MANAGEMENT GROUP LLP | New | +56.0k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | Added | +50.0k |
| Squarepoint Ops LLC | New | +49.8k |
| CITADEL ADVISORS LLC | New | +32.3k |
Biggest sellers
| FMR LLC | Reduced | -9.3m |
| Atika Capital Management LLC | Sold out | -355.0k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -150.0k |
| GSA CAPITAL PARTNERS LLP | Sold out | -131.1k |
| Jefferies Financial Group Inc. | Sold out | -55.0k |
| PFM Health Sciences, LP | Reduced | -50.9k |
| D. E. Shaw & Co., Inc. | Reduced | -46.3k |
| Ensign Peak Advisors, Inc | Sold out | -30.6k |
| SECTORAL ASSET MANAGEMENT INC | Reduced | -28.3k |
| Vontobel Holding Ltd. | Reduced | -28.3k |
Biggest calls
| GROUP ONE TRADING LLC | Reduced | $23.6k4.3k shares |
| CITADEL ADVISORS LLC | Reduced | $5.5k1.0k shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 shares |
Biggest puts
| CITADEL ADVISORS LLC | Added | $29.7k5.4k shares |
| SIMPLEX TRADING, LLC | Added | $4.0k800 shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 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.
No one currently above 5% in the filings since 19 Dec 2024.
Fell to 5% or below in the last year: Atlas Venture Fund X, L.P. (0.0%, 2026-05-14)
Holders, Q2 2023
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.00% of their portfolio | 8.6m $47.4m | Reduced -9.3m |
| Atlas Venture Life Science Advisors, LLC 5.67% of their portfolio | 8.3m $45.5m | Unchanged |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 7.5m $41.2m | Reduced -150.0k |
| Bellevue Group AG 0.28% of their portfolio | 3.6m $19.9m | Unchanged |
| BlackRock Inc. 0.00% of their portfolio | 3.5m $19.5m | Added +90.6k |
| T. Rowe Price Investment Management, Inc. 0.01% of their portfolio | 3.5m $19.3m | Added +130.5k |
| Artal Group S.A. 0.50% of their portfolio | 2.8m $15.5m | Unchanged |
| PFM Health Sciences, LP 0.57% of their portfolio | 2.6m $14.3m | Reduced -50.9k |
| VANGUARD GROUP INC 0.00% of their portfolio | 2.3m $12.4m | Added +16.6k |
| EcoR1 Capital, LLC 0.30% of their portfolio | 2.0m $11.3m | Added +90.3k |
| Yiheng Capital Management, L.P. 0.77% of their portfolio | 1.6m $8.8m | Unchanged |
| GREAT POINT PARTNERS LLC 1.13% of their portfolio | 1.0m $5.6m | Unchanged |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.0m $5.5m | Added +70.9k |
| STATE STREET CORP 0.00% of their portfolio | 908.7k $5.0m | Added +12.0k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 901.3k $5.0m | Added +437.5k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 721.0k $4.0m | Added +31.4k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 644.5k $3.5m | Added +99.7k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 530.4k $2.9m | Reduced -12.4k |
| MORGAN STANLEY 0.00% of their portfolio | 524.2k $2.9m | Added +10.4k |
| HARVARD MANAGEMENT CO INC 0.28% of their portfolio | 510.4k $2.8m | Unchanged |
| UBS Group AG 0.00% of their portfolio | 401.5k $2.2m | Added +14.2k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 383.5k $2.1m | Added +50.0k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 374.3k $2.1m | Reduced -10.8k |
| SECTORAL ASSET MANAGEMENT INC 0.33% of their portfolio | 356.7k $2.0m | Reduced -28.3k |
| Vontobel Holding Ltd. 0.02% of their portfolio | 356.7k $2.0m | Reduced -28.3k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 308.1k $1.7m | Added +21.1k |
| Nuveen Asset Management, LLC 0.00% of their portfolio | 272.3k $1.5m | Reduced -8.3k |
| TD Asset Management Inc 0.00% of their portfolio | 236.3k $1.3m | Added +4.8k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 166.4k $915.2k | Added +5.0k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 152.3k $837.5k | Reduced -449 |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 118.0k $649.0k | Added +31.4k |
| MARTINGALE ASSET MANAGEMENT L P 0.01% of their portfolio | 74.3k $408.7k | Unchanged |
| Invesco Ltd. 0.00% of their portfolio | 73.9k $406.4k | Reduced -705 |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 71.4k $392.9k | Reduced -3.5k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 69.8k $384.0k | Added +14.0k |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 66.4k $365.0k | Added +2.2k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 56.0k $307.9k | New |
| Squarepoint Ops LLC 0.00% of their portfolio | 49.8k $274.1k | New |
| CORNERCAP INVESTMENT COUNSEL INC 0.04% of their portfolio | 38.1k $209.3k | Added +9.4k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 36.2k $199.3k | Reduced -46.3k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 34.5k $189.6k | Unchanged |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 32.3k $177.6k | New |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 29.2k $160.6k | Reduced -10.1k |
| SVB FINANCIAL GROUP 0.29% of their portfolio | 27.9k $153.4k | Reduced -12.5k |
| TWO SIGMA ADVISERS, LP 0.00% of their portfolio | 27.5k $151.2k | Added +1.8k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 24.0k $132.2k | Added +8.2k |
| PDT Partners, LLC 0.02% of their portfolio | 22.2k $122.0k | Reduced -8.5k |
| AMERICAN INTERNATIONAL GROUP, INC. 0.00% of their portfolio | 21.8k $119.9k | Reduced -1.4k |
| Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio | 19.7k $108.6k | Added +13 |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 19.4k $106.7k | Added +8.8k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 19.2k $105.6k | Reduced -10.0k |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 18.9k $104.0k | Reduced -1.2k |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 17.8k $97.8k | Added +7.3k |
| BARCLAYS PLC 0.00% of their portfolio | 17.4k $95.7k | Reduced -12.8k |
| XTX Topco Ltd 0.02% of their portfolio | 16.8k $92.6k | New |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 15.1k $82.9k | Reduced -2.8k |
| CITIGROUP INC 0.00% of their portfolio | 14.6k $80.3k | Added +13.9k |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.00% of their portfolio | 12.9k $70.7k | New |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 12.8k $70.5k | Reduced -14.1k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 11.1k $61.0k | Added +2.0k |
| DENALI ADVISORS LLC 0.02% of their portfolio | 10.6k $58.3k | Unchanged |
| ProShare Advisors LLC 0.00% of their portfolio | 10.1k $55.8k | New |
| INNOVIS ASSET MANAGEMENT LLC 0.02% of their portfolio | 10.0k $55.1k | Reduced -9.9k |
| Legal & General Group Plc 0.00% of their portfolio | 4.8k $26.2k | Unchanged |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 4.6k $25.5k | New |
| AMALGAMATED BANK 0.00% of their portfolio | 4.4k $24.0k | Reduced -387 |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 4.1k $22.4k | Added +159 |
| Ameritas Investment Partners, Inc. 0.00% of their portfolio | 3.3k $18.0k | Unchanged |
| LAZARD ASSET MANAGEMENT LLC 0.00% of their portfolio | 3.1k $16.0k | Added +122 |
| Manchester Capital Management LLC 0.00% of their portfolio | 3.0k $16.5k | Unchanged |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 2.7k $14.6k | Reduced -40 |
| Metropolitan Life Insurance Co/NY 0.00% of their portfolio | 2.7k $14.6k | New |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 2.1k $11.4k | Unchanged |
| China Universal Asset Management Co., Ltd. 0.00% of their portfolio | 861 $4.7k | Added +53 |
| NISA INVESTMENT ADVISORS, LLC 0.00% of their portfolio | 840 $4.6k | Reduced -3.8k |
| Red Tortoise LLC 0.00% of their portfolio | 332 $1.8k | New |
| SIMPLEX TRADING, LLC 0.00% of their portfolio | 226 $1.0k | Reduced -23 |
| Daiwa Securities Group Inc. 0.00% of their portfolio | 194 $1.0k | Unchanged |
| State of Wyoming 0.00% of their portfolio | 138 $759 | Added +41 |
| First Horizon Advisors, Inc. 0.00% of their portfolio | 2 $11 | Unchanged |
| HUNTINGTON NATIONAL BANK 0.00% of their portfolio | 1 $6 | Unchanged |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. 0.00% of their portfolio | 0 $0 | Unchanged |