KRRONasdaqPharmaceutical PreparationsFiscal year ends December 31
Korro Bio, Inc.
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Aug 6, 2026
$8.91+0.42 (+4.95%)
Close on Oct 19, 2026
- Market cap
- $156.98M
- P/E (TTM)
- –
- Dividend yield
- –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
100.0%
15M of 15M shares
Institutional holders
107
21 new, 11 sold out
Net institutional buying
2M
In Q2 2026
Insider trades, 12 months
12 buys · 33 sales
Net bought $15.09M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Balyasny Asset Management L.P. | 951,783 | 6.60% | 13G (passive) amendment | Jun 30, 2026 |
| Steven A. Cohen | 816,885 | 5.70% | 13G (passive) | Mar 10, 2026 |
| BlackRock, Inc. | 747,546 | 5.20% | 13G (passive) | Jun 30, 2026 |
| Weston Nichols | 733,633 | 7.80% | 13G (passive) | Dec 23, 2025 |
| Daniel Mack | 600,000 | 6.37% | 13G (passive) | Dec 31, 2025 |
| Platanus Investment LLC | 540,165 | 6.80% | 13G (passive) | Nov 3, 2023 |
| Lynx1 Capital Management LP | 1,538,296 | 10.70% | 13G (passive) amendment | Mar 31, 2026 |
| VHCP Management III, LLC | 1,488,685 | 9.90% | 13G (passive) | Mar 10, 2026 |
| Ali Behbahani | 1,456,677 | 9.90% | 13D (active) amendment | Mar 10, 2026 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of KRRO | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| Lynx1 Capital Management LP | 1,538,296 | 10.45% | $20.27M | – | 2.34% |
| Nantahala Capital Management, LLC | 1,320,072 | 8.96% | $17.40M | +660,036 | 0.29% |
| NEA Management Company, LLC | 1,297,893 | 8.81% | $17.11M | – | 1.08% |
| VR Adviser, LLC | 1,009,500 | 6.86% | $13.31M | – | 0.40% |
| Atlas Venture Life Science Advisors, LLC | 962,884 | 6.54% | $12.69M | −174,265 | 1.44% |
| Balyasny Asset Management L.P. | 951,783 | 6.46% | $12.54M | −88,271 | 0.02% |
| BlackRock, Inc. | 817,621 | 5.55% | $10.78M | +357,615 | 0.00% |
| Affinity Asset Advisors, LLC | 706,904 | 4.80% | $9.32M | – | 0.42% |
| Adage Capital Partners Gp, L.L.C. | 540,968 | 3.67% | $7.13M | +312,568 | 0.01% |
| ADAR1 Capital Management, LLC | 540,054 | 3.67% | $7.12M | – | 0.33% |
| Vanguard Capital Management LLC | 454,778 | 3.09% | $5.99M | +143,865 | 0.00% |
| Driehaus Capital Management LLC | 450,045 | 3.06% | $5.93M | – | 0.03% |
| TCG Crossover Management, LLC | 416,301 | 2.83% | $5.49M | – | 0.13% |
| Kalehua Capital Management LLC | 405,040 | 2.75% | $5.34M | +295,664 | 1.70% |
| Siren, L.L.C. | 347,718 | 2.36% | $4.58M | – | 0.09% |
| Aqr Capital Management LLC | 298,974 | 2.03% | $3.94M | +31,219 | 0.00% |
| Geode Capital Management, LLC | 296,870 | 2.02% | $3.91M | +123,227 | 0.00% |
| 72 Investment Holdings, LLC | 276,831 | 1.88% | $3.65M | – | 7.30% |
| State Street Corp | 232,587 | 1.58% | $3.07M | +92,246 | 0.00% |
| Vanguard Portfolio Management LLC | 223,551 | 1.52% | $2.95M | +74,992 | 0.00% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 107 | 15M | 100.0% | 21 / 48 | 19 / 11 | 3M | 1M |
| Q1 2026 | 99 | 13M | 86.9% | 33 / 33 | 20 / 15 | 6M | 1M |
| Q4 2025 | 83 | 8M | 51.4% | 22 / 24 | 22 / 30 | 2M | 4M |
| Q3 2025 | 92 | 10M | 67.7% | 27 / 28 | 20 / 5 | 2M | 1M |
| Q2 2025 | 70 | 9M | 61.5% | 10 / 26 | 13 / 15 | 1M | 2M |
| Q1 2025 | 75 | 10M | 65.9% | 10 / 22 | 24 / 18 | 1M | 1M |
| Q4 2024 | 84 | 9M | 64.2% | 24 / 33 | 14 / 9 | 2M | 1M |
| Q3 2024 | 71 | 9M | 58.1% | 16 / 21 | 14 / 7 | 1M | 1M |
| Q2 2024 | 63 | 8M | 57.3% | 25 / 16 | 13 / 11 | 2M | 1M |
| Q1 2024 | 49 | 7M | 47.1% | 11 / 13 | 8 / 2 | 0M | 0M |
| Q4 2023 | 40 | 7M | 44.6% | 40 / 0 | 0 / 0 | 7M | 0M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
| Fund | Shares | % of KRRO | Value | % of fund | As of |
|---|---|---|---|---|---|
| Vanguard Total Stock Market Index Fund | 311,262 | 2.11% | $4.10M | 0.00% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 262,918 | 1.79% | $3.47M | 0.00% | Jun 30, 2026 |
| Vanguard Extended Market Index Fund | 135,396 | 0.92% | $1.78M | 0.00% | Jun 30, 2026 |
| Fidelity Small Cap Index Fund | 121,936 | 0.83% | $1.26M | 0.00% | Jul 31, 2026 |
| Vanguard Strategic Small-Cap Equity Fund | 106,395 | 0.72% | $1.40M | 0.04% | Jun 30, 2026 |
| iShares Russell 2000 Value ETF | 78,719 | 0.53% | $1.04M | 0.01% | Jun 30, 2026 |
| F/m Emerald Life Sciences Innovation ETF | 62,855 | 0.43% | $842.89K | 0.80% | May 31, 2026 |
| iShares Russell 2000 Growth ETF | 56,704 | 0.39% | $747.36K | 0.00% | Jun 30, 2026 |
| Fidelity Extended Market Index Fund | 35,064 | 0.24% | $470.21K | 0.00% | May 31, 2026 |
| Vanguard Russell 2000 Index Fund | 34,066 | 0.23% | $456.83K | 0.00% | May 31, 2026 |
| iShares Micro-Cap ETF | 34,046 | 0.23% | $448.73K | 0.03% | Jun 30, 2026 |
| Schwab Small-Cap Index Fund | 26,870 | 0.18% | $278.64K | 0.00% | Jul 31, 2026 |
| Vanguard Health Care Index Fund | 21,772 | 0.15% | $291.96K | 0.00% | May 31, 2026 |
| Master Small Cap Index Series | 18,948 | 0.13% | $249.73K | 0.00% | Jun 30, 2026 |
| Nuveen Small Cap Blend Index Fund | 14,880 | 0.10% | $154.31K | 0.00% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Ram Aiyar | President and CEO, Director | 73,659 | 0.50% | Aug 5, 2026 |
| Oliver Dolan | Senior Vice President, Finance | 16,241 | 0.11% | Sep 14, 2026 |
| Todd Chappell | Chief Operating Officer | 24,464 | 0.17% | Jul 17, 2026 |
| Jeffrey Cerio | General Counsel | 41,793 | 0.28% | Jul 17, 2026 |
| Loic A. Vincent | Chief Scientific Officer | 25,797 | 0.18% | Jul 17, 2026 |
| Olukemi Olugemo | Chief Medical Officer | – | – | Feb 5, 2025 |
| Vineet Agarwal | Chief Financial Officer | 800 | 0.01% | Feb 5, 2025 |
| Jean Francois Formela | Director | 132,650 | 0.90% | Sep 15, 2026 |
| Katharine Knobil | Director | – | – | Jun 11, 2026 |
| Timothy R. Pearson | Director | – | – | Jun 11, 2026 |
| Ali Behbahani | Director | 1,297,893 | 8.81% | Jun 11, 2026 |
| Nessan Bermingham | Director | 35,114 | 0.24% | Jun 11, 2026 |
| Rachel Meyers | Director | – | – | Jun 11, 2026 |
| Weston Nichols | 10% owner | 1,538,296 | 10.45% | Aug 13, 2026 |
| Capital Management LP Lynx1 | 10% owner | 1,544,980 | 10.49% | Aug 13, 2026 |
| NEA Partners 17, L.P. | 10% owner | 1,090,793 | 7.41% | Mar 12, 2026 |
| Nea 17 Gp, Llc | 10% owner | 1,072,936 | 7.29% | Mar 12, 2026 |
| Rick Yang | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Mohamad Makhzoumi | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Paul Edward Walker | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Edward T. Mathers | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Scott D. Sandell | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Forest Baskett | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Carmen Chang | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| Anthony A. Florence Jr. | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
| New Enterprise Associates 17, L.P. | 10% owner | 1,297,893 | 8.81% | Mar 12, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Jean Francois Formela Director | Sep 14, 2026 | Sale(10b5-1 plan) | −6,602 | $14.12 | $93.22K | 132,650 |
| Jean Francois Formela Director | Sep 14, 2026 | Sale(10b5-1 plan) | −31,888 | $14.12 | $450.26K | 640,610 |
| Jean Francois Formela Director | Sep 11, 2026 | Sale(10b5-1 plan) | −8,450 | $13.99 | $118.22K | 672,498 |
| Jean Francois Formela Director | Sep 11, 2026 | Sale(10b5-1 plan) | −1,750 | $13.99 | $24.48K | 139,252 |
| Oliver Dolan Senior Vice President, Finance | Sep 11, 2026 | Sale(10b5-1 plan) | −5 | $13.72 | $69 | 16,241 |
| Oliver Dolan Senior Vice President, Finance | Sep 9, 2026 | Sale(10b5-1 plan) | −6 | $13.60 | $82 | 16,246 |
| Oliver Dolan Senior Vice President, Finance | Sep 8, 2026 | Sale(10b5-1 plan) | −7,347 | $13.51 | $99.26K | 16,252 |
| Jean Francois Formela Director | Aug 26, 2026 | Sale(10b5-1 plan) | −51 | $13.96 | $712 | 141,002 |
| Jean Francois Formela Director | Aug 26, 2026 | Sale(10b5-1 plan) | −249 | $13.96 | $3.48K | 680,948 |
| Jean Francois Formela Director | Aug 19, 2026 | Sale(10b5-1 plan) | −4,884 | $14.00 | $68.38K | 141,053 |
| Jean Francois Formela Director | Aug 19, 2026 | Sale(10b5-1 plan) | −23,584 | $14.00 | $330.18K | 681,197 |
| Jean Francois Formela Director | Aug 11, 2026 | Sale(10b5-1 plan) | −368 | $13.96 | $5.14K | 145,937 |
| Jean Francois Formela Director | Aug 11, 2026 | Sale(10b5-1 plan) | −1,775 | $13.96 | $24.78K | 704,781 |
| Capital Management LP Lynx1 10% owner | Aug 10, 2026 | Buy | +1,462 | $13.19 | $19.28K | 1,544,980 |
| Capital Management LP Lynx1 10% owner | Aug 6, 2026 | Buy | +5,222 | $11.40 | $59.53K | 1,543,518 |
| Ram Aiyar President and CEO, Director | Aug 4, 2026 | Sale | −5,802 | $10.84 | $62.89K | 69,046 |
| Loic A. Vincent Chief Scientific Officer | Jul 15, 2026 | Award | +7,500 | – | – | 25,797 |
| Jeffrey Cerio General Counsel | Jul 15, 2026 | Award | +6,500 | – | – | 41,793 |
| Todd Chappell Chief Operating Officer | Jul 15, 2026 | Award | +7,500 | – | – | 24,464 |
| Oliver Dolan Senior Vice President, Finance | Jul 15, 2026 | Award | +5,500 | – | – | 23,599 |
| Jean Francois Formela Director | Jul 6, 2026 | Sale(10b5-1 plan) | −8,506 | $13.96 | $118.74K | 146,305 |
| Jean Francois Formela Director | Jul 6, 2026 | Sale(10b5-1 plan) | −817 | $13.96 | $11.41K | 706,556 |
| Jean Francois Formela Director | Jul 2, 2026 | Sale(10b5-1 plan) | −14,745 | $14.03 | $206.87K | 154,811 |
| Jean Francois Formela Director | Jul 2, 2026 | Sale(10b5-1 plan) | −85,955 | $14.03 | $1.21M | 707,373 |
| Jean Francois Formela Director | Jun 24, 2026 | Sale(10b5-1 plan) | −6,979 | $14.60 | $101.89K | 169,670 |
| Jean Francois Formela Director | Jun 24, 2026 | Sale(10b5-1 plan) | −666 | $14.98 | $9.98K | 793,328 |
| Jean Francois Formela Director | Jun 24, 2026 | Sale(10b5-1 plan) | −114 | $14.98 | $1.71K | 169,556 |
| Jean Francois Formela Director | Jun 24, 2026 | Sale(10b5-1 plan) | −40,679 | $14.60 | $593.91K | 793,994 |
| Jean Francois Formela Director | Jun 23, 2026 | Sale(10b5-1 plan) | −17,426 | $14.25 | $248.32K | 176,649 |
| Jean Francois Formela Director | Jun 23, 2026 | Sale(10b5-1 plan) | −101,579 | $14.25 | $1.45M | 834,673 |
| Jean Francois Formela Director | Jun 22, 2026 | Sale(10b5-1 plan) | −580 | $13.95 | $8.09K | 194,075 |
| Jean Francois Formela Director | Jun 22, 2026 | Sale(10b5-1 plan) | −3,382 | $13.95 | $47.18K | 936,252 |
| Oliver Dolan Senior Vice President, Finance | Jun 16, 2026 | Sale | −3,383 | $10.83 | $36.64K | 18,099 |
| Loic A. Vincent Chief Scientific Officer | Jun 16, 2026 | Sale | −3,418 | $10.83 | $37.02K | 18,297 |
| Jeffrey Cerio General Counsel | Jun 16, 2026 | Sale | −6,609 | $10.83 | $71.58K | 35,293 |
| Todd Chappell Chief Operating Officer | Jun 16, 2026 | Sale | −3,168 | $10.83 | $34.31K | 16,964 |
| Ram Aiyar President and CEO, Director | May 29, 2026 | Sale | −15,152 | $12.98 | $196.67K | 74,848 |
| Jean Francois Formela Director | May 28, 2026 | Sale(10b5-1 plan) | −419 | $13.95 | $5.85K | 194,655 |
| Jean Francois Formela Director | May 28, 2026 | Sale(10b5-1 plan) | −2,441 | $13.95 | $34.05K | 939,634 |
| Ram Aiyar President and CEO, Director | May 26, 2026 | Award | +50,000 | $12.33 | $616.50K | 90,000 |
| Weston Nichols 10% owner | Mar 31, 2026 | Buy | +520 | $10.60 | $5.51K | 1,538,296 |
| Ali Behbahani Director, 10% owner | Mar 10, 2026 | Award | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Mohamad Makhzoumi 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Carmen Chang 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Rick Yang 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| New Enterprise Associates 17, L.P. 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Forest Baskett 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Paul Edward Walker 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Scott D. Sandell 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Edward T. Mathers 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Anthony A. Florence Jr. 10% owner | Mar 10, 2026 | Buy | +207,100 | $11.11 | $2.30M | 1,297,893 |
| Ram Aiyar President and CEO, Director | Feb 2, 2026 | Award | +40,000 | – | – | 40,000 |
| Oliver Dolan Senior Vice President, Finance | Dec 15, 2025 | Award | +21,482 | – | – | 21,482 |
| Loic A. Vincent Chief Scientific Officer | Dec 15, 2025 | Award | +21,715 | – | – | 21,715 |
| Todd Chappell Chief Operating Officer | Dec 15, 2025 | Award | +20,132 | – | – | 20,132 |
| Jeffrey Cerio General Counsel | Dec 15, 2025 | Award | +41,902 | – | – | 41,902 |
| Vineet Agarwal Chief Financial Officer | Nov 11, 2024 | Option exercise | +800 | $11.68 | $9.34K | 800 |
| Vineet Agarwal Chief Financial Officer | Nov 11, 2024 | Sale(10b5-1 plan) | −800 | $70.00 | $56.00K | 0 |
| Vineet Agarwal Chief Financial Officer | Oct 17, 2024 | Sale(10b5-1 plan) | −115 | $74.56 | $8.57K | 7,914 |
| Vineet Agarwal Chief Financial Officer | Oct 17, 2024 | Sale(10b5-1 plan) | −23 | $77.00 | $1.77K | 7,835 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Atlas Venture Fund XI, L.P. Shareholder | Sep 14, 2026 | 31,888 | $440.37K | Sep 14, 2026 | Private Placement |
| Atlas Venture Opportunity Fund II, L.P. Shareholder | Sep 14, 2026 | 6,602 | $91.17K | Sep 14, 2026 | Private Placement |
| Atlas Venture Fund XI, L.P. Shareholder | Sep 11, 2026 | 8,450 | $110.36K | Sep 11, 2026 | Private Placement |
| Atlas Venture Opportunity Fund II, L.P. Shareholder | Sep 11, 2026 | 1,750 | $22.86K | Sep 11, 2026 | Private Placement |
| Oliver Dolan Officer | Sep 11, 2026 | 5 | $69 | Sep 11, 2026 | Restricted Stock Vesting |
| Oliver Dolan Officer | Sep 9, 2026 | 6 | $82 | Sep 9, 2026 | Restricted Stock Vesting |
| Oliver Dolan Officer | Sep 8, 2026 | 7,347 | $99.29K | Sep 8, 2026 | Restricted Stock Vesting |
| Atlas Venture Fund XI, L.P. Shareholder | Aug 26, 2026 | 249 | $3.42K | Aug 26, 2026 | Private Placement |
| Atlas Venture Opportunity Fund II, L.P. Shareholder | Aug 26, 2026 | 51 | $700 | Aug 26, 2026 | Private Placement |
| Atlas Venture Opportunity Fund II, L.P. Shareholder | Aug 19, 2026 | 4,884 | $64.57K | Aug 19, 2026 | Private Placement |
| Atlas Venture Fund XI, L.P. Shareholder | Aug 19, 2026 | 23,584 | $311.78K | Aug 19, 2026 | Private Placement |
| Atlas Venture Opportunity Fund II, L.P. Shareholder | Aug 11, 2026 | 368 | $4.96K | Aug 11, 2026 | Private Placement |
| Atlas Venture Fund XI, L.P. Shareholder | Aug 11, 2026 | 1,775 | $23.94K | Aug 11, 2026 | Private Placement |
| Ram Aiyar Officer, Director | Aug 4, 2026 | 5,802 | $662.92K | Aug 4, 2026 | Restricted Stock Vesting |
| Atlas Venture Fund XI, L.P. Shareholder | Jul 6, 2026 | 817 | $11.44K | Jul 6, 2026 | Private Placement |