KEROS THERAPEUTICS INC KROS
COM · Common Stock · CUSIP 492327101 · ISIN US4923271013
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersLexington, 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 ($14.7k this quarter). Holder counts are more reliable. Shares outstanding: 40.6m as of 2025-05-01, 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 ≈ $11.68. Options: 11 managers hold calls ($12.5m notional), 11 hold puts ($17.0m).
Trends to Q1 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 113 |
| Q4 2022 | 126 |
| Q1 2023 | 130 |
| Q2 2023 | 125 |
| Q3 2023 | 108 |
| Q4 2023 | 122 |
| Q1 2024 | 148 |
| Q2 2024 | 153 |
| Q3 2024 | 165 |
| Q4 2024 | 162 |
| Q1 2025 | 158 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2023 | 73 | 49 |
| Q3 2023 | 52 | 49 |
| Q4 2023 | 64 | 43 |
| Q1 2024 | 94 | 49 |
| Q2 2024 | 84 | 58 |
| Q3 2024 | 92 | 61 |
| Q4 2024 | 100 | 70 |
| Q1 2025 | 94 | 90 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2024 | $1.7m | $86.3k | 0.05 |
| Q3 2024 | $4.5m | $527.6k | 0.12 |
| Q4 2024 | $10.8m | $11.2m | 1.04 |
| Q1 2025 | $12.5m | $17.0m | 1.36 |
Biggest buyers
| JPMORGAN CHASE & CO | Added | +2.4m |
| Logos Global Management LP | New | +2.0m |
| ADAR1 Capital Management, LLC | Added | +1.5m |
| D. E. Shaw & Co., Inc. | Added | +1.3m |
| TANG CAPITAL MANAGEMENT LLC | New | +1.1m |
| FEDERATED HERMES, INC. | Added | +1.1m |
| MORGAN STANLEY | Added | +1.0m |
| VANGUARD GROUP INC | Added | +609.2k |
| Nantahala Capital Management, LLC | Added | +591.7k |
| DRW Securities, LLC | New | +464.9k |
Biggest sellers
| FMR LLC | Reduced | -5.1m |
| BRAIDWELL LP | Sold out | -1.9m |
| Darwin Global Management, Ltd. | Sold out | -1.7m |
| Holocene Advisors, LP | Sold out | -1.2m |
| Jefferies Financial Group Inc. | Sold out | -866.7k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -866.5k |
| MANGROVE PARTNERS IM, LLC | Sold out | -736.4k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -645.0k |
| CITADEL ADVISORS LLC | Reduced | -599.5k |
| TCG Crossover Management, LLC | Reduced | -550.0k |
Biggest calls
| Nantahala Capital Management, LLC | Unchanged | $2.5m250.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $2.1m202.3k shares |
| SIMPLEX TRADING, LLC | Added | $2.1m202.1k shares |
| CITADEL ADVISORS LLC | Added | $1.7m165.1k shares |
| DIADEMA PARTNERS LP | Added | $1.5m147.1k shares |
| MILLENNIUM MANAGEMENT LLC | New | $917.1k90.0k shares |
| GROUP ONE TRADING LLC | Added | $858.0k84.2k shares |
| JANE STREET GROUP, LLC | Reduced | $544.1k53.4k shares |
| Caption Management, LLC | Unchanged | $305.7k30.0k shares |
| Persistent Asset Partners Ltd | Unchanged | $10.8k354 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $4.8m473.1k shares |
| Caption Management, LLC | New | $4.0m392.9k shares |
| GROUP ONE TRADING LLC | Added | $1.9m186.3k shares |
| CITADEL ADVISORS LLC | Added | $1.4m138.7k shares |
| JANE STREET GROUP, LLC | Reduced | $1.4m136.4k shares |
| SIMPLEX TRADING, LLC | Added | $1.4m133.1k shares |
| Centiva Capital, LP | New | $1.0m100.5k shares |
| DIADEMA PARTNERS LP | Added | $670.5k65.8k shares |
| Persistent Asset Partners Ltd | Unchanged | $380.8k153 shares |
| HAP Trading, LLC | New | $66.0k80.0k 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 |
|---|---|
| BlackRock Portfolio Management LLC 13G · institution +3.4 pts · filed 2026-10-27 | 9.1% |
| BlackRock, Inc. 13G · institution -1.7 pts · filed 2026-07-29 | 8.4% |
| Nantahala Capital Management, LLC 13G · institution new · filed 2026-05-15 | 6.9% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-27), D. E. SHAW & CO, L.P. (3.9%, 2026-02-17), TANG CAPITAL MANAGEMENT LLC (0.0%, 2026-02-17), ExodusPoint Capital Management, LP (0.0%, 2026-02-17), Madison Avenue Partners, LP (2.7%, 2026-02-17)
Insider purchases and sales in Q1 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 |
|---|---|---|---|---|---|
| Q2 2023 | 0 | — | 1 | $1.9m | $1.9m |
| Q3 2023 | 0 | — | 0 | — | — |
| Q4 2023 | 0 | — | 0 | — | — |
| Q1 2024 | 0 | — | 1 | $1.8m | — |
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 0 | — | 2 | $11.0m | — |
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
None reported in Q1 2025.
Holders, Q1 2025
| Manager | Shares | Change |
|---|---|---|
| Nuveen, LLC 0.03% of their portfolio | 3.9m $94.5m | First filing |
| BlackRock, Inc. 0.00% of their portfolio | 2.8m $28.4m | Added +56.0k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 2.6m $26.5m | Added +2.4m |
| VANGUARD GROUP INC 0.00% of their portfolio | 2.6m $26.2m | Added +609.2k |
| Logos Global Management LP 3.62% of their portfolio | 2.0m $20.4m | New |
| MORGAN STANLEY 0.00% of their portfolio | 1.7m $17.3m | Added +1.0m |
| Nantahala Capital Management, LLC 1.27% of their portfolio | 1.5m $15.4m | Added +591.7k |
| ADAR1 Capital Management, LLC 2.91% of their portfolio | 1.5m $15.1m | Added +1.5m |
| STATE STREET CORP 0.00% of their portfolio | 1.3m $13.3m | Added +99.2k |
| D. E. Shaw & Co., Inc. 0.02% of their portfolio | 1.3m $12.9m | Added +1.3m |
| FEDERATED HERMES, INC. 0.03% of their portfolio | 1.2m $12.5m | Added +1.1m |
| TANG CAPITAL MANAGEMENT LLC 0.62% of their portfolio | 1.1m $11.2m | New |
| ORBIMED ADVISORS LLC 0.25% of their portfolio | 1.0m $10.4m | Unchanged |
| ALKEON CAPITAL MANAGEMENT LLC 0.05% of their portfolio | 850.5k $8.7m | Reduced -250.5k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 806.2k $8.2m | Added +40.7k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 740.6k $7.5m | Added +205.0k |
| Redmile Group, LLC 0.53% of their portfolio | 552.5k $5.6m | Unchanged |
| DRW Securities, LLC 0.40% of their portfolio | 464.9k $4.7m | New |
| FMR LLC 0.00% of their portfolio | 441.5k $4.5m | Reduced -5.1m |
| Rangeley Capital, LLC 4.69% of their portfolio | 408.2k $4.2m | New |
| Catalio Capital Management, LP 0.98% of their portfolio | 389.4k $4.0m | Reduced -17.9k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 290.0k $3.0m | Reduced -6.5k |
| PDT Partners, LLC 0.20% of their portfolio | 276.1k $2.8m | New |
| Ikarian Capital, LLC 0.91% of their portfolio | 274.0k $2.8m | New |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 273.3k $2.8m | New |
| Blue Owl Capital Holdings LP 0.87% of their portfolio | 266.0k $2.7m | Added +23.4k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 241.9k $2.5m | Reduced -37.8k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 233.2k $2.4m | Reduced -645.0k |
| Parkman Healthcare Partners LLC 0.26% of their portfolio | 217.8k $2.2m | Reduced -96.8k |
| Cubist Systematic Strategies, LLC 0.03% of their portfolio | 198.4k $2.0m | Added +197.2k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 191.6k $2.0m | Reduced -599.5k |
| EcoR1 Capital, LLC 0.11% of their portfolio | 187.5k $1.9m | Unchanged |
| Tetragon Partners GP Ltd 0.60% of their portfolio | 183.0k $1.9m | Added +80.0k |
| 22NW, LP 1.22% of their portfolio | 179.0k $1.8m | New |
| RBF Capital, LLC 0.11% of their portfolio | 170.0k $1.7m | New |
| Clearbridge Investments, LLC 0.00% of their portfolio | 156.7k $1.6m | Reduced -33.3k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 155.6k $1.6m | Reduced -5.9k |
| Walleye Capital LLC 0.02% of their portfolio | 150.5k $1.5m | Reduced -47.2k |
| ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio | 147.6k $1.5m | New |
| Western Standard LLC 0.81% of their portfolio | 134.9k $1.4m | New |
| DAFNA Capital Management LLC 0.38% of their portfolio | 130.3k $1.3m | Unchanged |
| Connor, Clark & Lunn Investment Management Ltd. 0.01% of their portfolio | 128.1k $1.3m | Added +99.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 121.8k $1.2m | Reduced -89.5k |
| TWO SIGMA ADVISERS, LP 0.00% of their portfolio | 119.5k $1.2m | Added +98.8k |
| OCONNOR, A Distinct Business Unit of UBS ASSET MANAGEMENT AMERICAS (LLC) 0.03% of their portfolio | 115.5k $1.2m | Added +64.6k |
| Nebula Research & Development LLC 0.11% of their portfolio | 115.4k $1.2m | Added +43.7k |
| Caption Management, LLC 0.05% of their portfolio | 107.0k $1.1m | Added +45.8k |
| Engineers Gate Manager LP 0.02% of their portfolio | 106.9k $1.1m | Added +6.9k |
| PFM Health Sciences, LP 0.08% of their portfolio | 104.3k $1.1m | Unchanged |
| Jump Financial, LLC 0.02% of their portfolio | 103.8k $1.1m | New |
| Stonepine Capital Management, LLC 0.99% of their portfolio | 100.0k $1.0m | New |
| Bank of New York Mellon Corp 0.00% of their portfolio | 97.8k $996.1k | Reduced -123 |
| TWINBEECH CAPITAL LP 0.02% of their portfolio | 97.7k $995.3k | Reduced -31.9k |
| UBS Group AG 0.00% of their portfolio | 92.4k $941.9k | Reduced -82.5k |
| Centiva Capital, LP 0.05% of their portfolio | 90.0k $917.1k | New |
| MONIMUS CAPITAL MANAGEMENT, LP 0.73% of their portfolio | 84.1k $856.5k | New |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 81.9k $834.9k | First filing |
| BOOTHBAY FUND MANAGEMENT, LLC 0.03% of their portfolio | 81.3k $828.1k | New |
| CITIGROUP INC 0.00% of their portfolio | 71.8k $731.2k | Added +17.3k |
| SIMPLEX TRADING, LLC 0.03% of their portfolio | 70.5k $718.0k | Added +63.1k |
| Brevan Howard Capital Management LP 0.02% of their portfolio | 65.8k $671.0k | Added +54.7k |
| Assenagon Asset Management S.A. 0.00% of their portfolio | 64.9k $661.7k | Unchanged |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 62.4k $635.6k | Added +28.7k |
| BARCLAYS PLC 0.00% of their portfolio | 59.9k $610.0k | Reduced -47.7k |
| Rafferty Asset Management, LLC 0.00% of their portfolio | 55.3k $563.8k | Added +9.5k |
| HighVista Strategies LLC 0.20% of their portfolio | 52.1k $531.0k | Unchanged |
| GROUP ONE TRADING LLC 0.02% of their portfolio | 49.7k $506.4k | Added +48.6k |
| XTX Topco Ltd 0.03% of their portfolio | 48.1k $490.4k | New |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 46.9k $478.4k | Reduced -54.2k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 44.7k $455.2k | Added +3.8k |
| Squarepoint Ops LLC 0.00% of their portfolio | 44.0k $448.2k | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 43.2k $441.0k | Reduced -866.5k |
| Verition Fund Management LLC 0.00% of their portfolio | 41.3k $420.9k | Reduced -174.8k |
| Tejara Capital Ltd 0.20% of their portfolio | 40.2k $410.1k | New |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 38.3k $390.2k | Reduced -250.1k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 36.6k $374.0k | Reduced -118.5k |
| Woodline Partners LP 0.00% of their portfolio | 35.9k $365.6k | Reduced -351.8k |
| Man Group plc 0.00% of their portfolio | 34.0k $346.6k | New |
| Invesco Ltd. 0.00% of their portfolio | 33.3k $339.0k | Added +20.6k |
| SummitTX Capital, L.P. 0.01% of their portfolio | 30.9k $314.7k | First filing |
| ALPS ADVISORS INC 0.00% of their portfolio | 29.7k $303.0k | Reduced -3.0k |
| Quadrature Capital Ltd 0.01% of their portfolio | 28.9k $293.0k | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 28.5k $290.5k | Reduced -108.9k |
| ALGERT GLOBAL LLC 0.01% of their portfolio | 27.5k $280.0k | Added +14.8k |
| Quinn Opportunity Partners LLC 0.02% of their portfolio | 25.0k $254.8k | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 23.0k $234.0k | Reduced -4.0k |
| HAP Trading, LLC 0.08% of their portfolio | 22.6k $229.8k | New |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 22.2k $227.4k | Added +3.0k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 22.1k $225.6k | New |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 21.1k $215.2k | Added +2.2k |
| Erste Asset Management GmbH 0.00% of their portfolio | 20.7k $223.4k | Unchanged |
| Jain Global LLC 0.00% of their portfolio | 20.0k $203.7k | Reduced -31.3k |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 19.9k $202.4k | Added +4.5k |
| FOX RUN MANAGEMENT, L.L.C. 0.03% of their portfolio | 19.0k $193.5k | Reduced -3.2k |
| ExodusPoint Capital Management, LP 0.00% of their portfolio | 19.0k $193.0k | New |
| Shay Capital LLC 0.06% of their portfolio | 18.8k $191.9k | New |
| Corton Capital Inc. 0.61% of their portfolio | 18.2k $185.6k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 18.1k $184.4k | Unchanged |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO 0.00% of their portfolio | 17.7k $180.1k | Unchanged |
| Creative Planning 0.00% of their portfolio | 17.3k $176.1k | New |