KRRO on Nasdaq
Korro Bio, Inc.
In its 2026 annual report the company says: “We are a biopharmaceutical company with a mission to discover, develop and commercialize a new class of genetic medicines based on editing RNA, enabling the treatment of both rare and highly prevalent diseases. We are generating a portfolio of differentiated programs that are designed to harness the body’s natural RNA editing process to effect a precise yet transient change to a single nucleoside (adenosine to an inosine edit).”3 It is headquartered in Cambridge, Massachusetts.1 Its shares trade on Nasdaq under the symbol KRRO.1
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Last updated Oct 21, 2026.
Overview
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- TickerKRRO on Nasdaq1
- IndustryPharmaceutical Preparations1
- HeadquartersCambridge, Massachusetts1
- Incorporated inDE2
- Business address60 First Street, 2Nd Floor, Suite 250, Cambridge, Ma 021412
- Filer categoryNon-accelerated filer, Smaller reporting company2
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We are a biopharmaceutical company with a mission to discover, develop and commercialize a new class of genetic medicines based on editing RNA, enabling the treatment of both rare and highly prevalent diseases. We are generating a portfolio of differentiated programs that are designed to harness the body’s natural RNA editing process to effect a precise yet transient change to a single nucleoside (adenosine to an inosine edit). By editing RNA instead of DNA, we are expanding the reach of genetic medicines by delivering additional precision and tunability, which has the potential for increased specificity and improved long-term tolerability. We use an oligonucleotide-based approach and expect to bring our medicines to patients by leveraging our proprietary platform with precedented delivery modalities, including N-acetylgalactosamine, or GalNAc, -conjugated delivery for subcutaneous admin…3 From its latest annual report
Financials
From the company’s reports to the SEC. Every number links to the filing it came from.
Key numbers, fiscal 2025
-1906.4%Operating margin4
-1834.5%Net margin4
181.5%Revenue growth, 20254
-228.0%Return on equity4
-$79.1MFree cash flow4
Where the money goes
Where each dollar of revenue went, fiscal 2025
- Research and development99¢$65.6M
- Income tax1¢$637.0K
Out of $6.4M in revenue.4 The company lost money this year.
Financial statements
Every line of the income statement as filed: the last 2 fiscal years, latest first.4
| Period ending | 2025-12-31 | 2024-12-31 |
|---|---|---|
| Collaboration revenue | $6.4M | $2.3M |
| Research and development | $65.6M | $63.6M |
| General and administrative | $28.2M | $30.5M |
| Long-lived asset impairment charge | $30.9M | $0 |
| Restructuring charge | $3.6M | $0 |
| Total operating expenses | $128.2M | $94.2M |
| Loss from operations | -$121.9M | -$91.9M |
| Other income, net | $5.2M | $8.5M |
| Total other income, net | $5.2M | $8.5M |
| Loss before provision for income taxes | -$116.6M | -$83.4M |
| Provision for income taxes | -$637.0K | -$141.0K |
| Net loss | -$117.3M | -$83.6M |
| Unrealized (loss) gain on available-for-sale marketable securities | -$26.0K | $184.0K |
| Foreign currency translation adjustments, net | -$30.0K | $84.0K |
| Comprehensive loss | -$117.3M | -$83.3M |
| Net loss per share, basic | -$12.48 | -$9.37 |
| Net loss per share, diluted | -$12.48 | -$9.37 |
| Weighted-average shares used in computing net loss per share, basic | 9.4M shares | 8.9M shares |
| Weighted-average shares used in computing net loss per share, diluted | 9.4M shares | 8.9M shares |
No quarter-by-quarter statement was filed.
Every line of the balance sheet as filed: the last 3 fiscal years (annual) or 3 quarters (quarterly), latest first.4
| Period ending | 2025-12-31 | 2024-12-31 | 2023-12-31 |
|---|---|---|---|
| Cash and cash equivalents | $21.8M | $55.6M | |
| Short-term marketable securities | $53.3M | $70.5M | |
| Accounts receivable | $969.0K | $1.7M | |
| Prepaid expenses and other current assets | $6.2M | $3.7M | |
| Total current assets | $82.4M | $131.5M | |
| Property and equipment, net | $8.2M | $27.7M | |
| Operating lease right-of-use assets | $8.1M | $23.8M | |
| Restricted cash, net of current portion | $2.4M | $3.4M | |
| Long-term marketable securities | $10.0M | $37.0M | |
| Other non-current assets | $2.5M | $2.8M | |
| Total assets | $113.5M | $226.2M | |
| Accounts payable | $1.7M | $4.0M | |
| Accrued expenses and other current liabilities | $7.6M | $6.2M | |
| Operating lease liabilities, current portion | $2.7M | $1.3M | |
| Deferred revenue, current portion | $0 | $3.5M | |
| Total current liabilities | $11.9M | $15.0M | |
| Operating lease liabilities, net of current portion | $40.8M | $43.5M | |
| Deferred revenue, net of current portion | $7.8M | $5.9M | |
| Other non-current liabilities | $1.5M | $1.5M | |
| Total liabilities | $62.1M | $65.8M | |
| Preferred stock, $0.001 par value; 10,000,000 shares authorized at December 31, 2025 and December 31, 2024; no shares issued and outstanding at December 31, 2025 and December 31, 2024 | $0 | $0 | |
| Common stock, $0.001 par value; 200,000,000 shares authorized at December 31, 2025 and December 31, 2024; 9,417,295 shares and 9,377,259 shares issued and outstanding at December 31, 2025 and December 31, 2024, respectively | $9.0K | $9.0K | |
| Additional paid-in capital | $435.1M | $426.7M | |
| Accumulated other comprehensive income | $212.0K | $268.0K | |
| Accumulated deficit | -$383.8M | -$266.6M | |
| Total stockholders' equity | $51.4M | $160.4M | $169.9M |
| Total liabilities and stockholders' equity | $113.5M | $226.2M | |
| Preferred stock, par value | $0.00 | $0.00 | |
| Preferred stock, shares authorized | 10.0M shares | 10.0M shares | |
| Preferred stock, shares issued | 0 shares | 0 shares | |
| Preferred stock, shares outstanding | 0 shares | 0 shares | |
| Common stock, par value | $0.00 | $0.00 | |
| Common stock, shares authorized | 200.0M shares | 200.0M shares | |
| Common stock shares issued and sold | 9.4M shares | 9.4M shares | |
| Common stock, shares outstanding | 9.4M shares | 9.4M shares |
| Period ending | 2025-12-31 | 2024-12-31 | 2023-12-31 |
|---|---|---|---|
| Cash and cash equivalents | $21.8M | $55.6M | |
| Short-term marketable securities | $53.3M | $70.5M | |
| Accounts receivable | $969.0K | $1.7M | |
| Prepaid expenses and other current assets | $6.2M | $3.7M | |
| Total current assets | $82.4M | $131.5M | |
| Property and equipment, net | $8.2M | $27.7M | |
| Operating lease right-of-use assets | $8.1M | $23.8M | |
| Restricted cash, net of current portion | $2.4M | $3.4M | |
| Long-term marketable securities | $10.0M | $37.0M | |
| Other non-current assets | $2.5M | $2.8M | |
| Total assets | $113.5M | $226.2M | |
| Accounts payable | $1.7M | $4.0M | |
| Accrued expenses and other current liabilities | $7.6M | $6.2M | |
| Operating lease liabilities, current portion | $2.7M | $1.3M | |
| Deferred revenue, current portion | $0 | $3.5M | |
| Total current liabilities | $11.9M | $15.0M | |
| Operating lease liabilities, net of current portion | $40.8M | $43.5M | |
| Deferred revenue, net of current portion | $7.8M | $5.9M | |
| Other non-current liabilities | $1.5M | $1.5M | |
| Total liabilities | $62.1M | $65.8M | |
| Preferred stock, $0.001 par value; 10,000,000 shares authorized at December 31, 2025 and December 31, 2024; no shares issued and outstanding at December 31, 2025 and December 31, 2024 | $0 | $0 | |
| Common stock, $0.001 par value; 200,000,000 shares authorized at December 31, 2025 and December 31, 2024; 9,417,295 shares and 9,377,259 shares issued and outstanding at December 31, 2025 and December 31, 2024, respectively | $9.0K | $9.0K | |
| Additional paid-in capital | $435.1M | $426.7M | |
| Accumulated other comprehensive income | $212.0K | $268.0K | |
| Accumulated deficit | -$383.8M | -$266.6M | |
| Total stockholders' equity | $51.4M | $160.4M | $169.9M |
| Total liabilities and stockholders' equity | $113.5M | $226.2M | |
| Preferred stock, par value | $0.00 | $0.00 | |
| Preferred stock, shares authorized | 10.0M shares | 10.0M shares | |
| Preferred stock, shares issued | 0 shares | 0 shares | |
| Preferred stock, shares outstanding | 0 shares | 0 shares | |
| Common stock, par value | $0.00 | $0.00 | |
| Common stock, shares authorized | 200.0M shares | 200.0M shares | |
| Common stock shares issued and sold | 9.4M shares | 9.4M shares | |
| Common stock, shares outstanding | 9.4M shares | 9.4M shares |
Cash flow is reported year to date, not quarter by quarter, so there are no separate quarterly figures.
Every line of the cash flow as filed: the last 2 fiscal years, latest first.4
| Period ending | 2025-12-31 | 2024-12-31 |
|---|---|---|
| Net loss | -$117.3M | -$83.6M |
| Non-cash lease expense | $730.0K | $3.3M |
| Stock-based compensation expense | $7.7M | $4.5M |
| Depreciation expense | $4.3M | $3.6M |
| Long-lived asset impairment charge | $30.9M | $0 |
| Net amortization of premiums and discounts on marketable securities | -$489.0K | -$1.8M |
| Loss on disposal of property and equipment | $63.0K | $357.0K |
| Accounts receivable | $727.0K | -$1.7M |
| Prepaid expenses and other current assets | -$1.7M | -$726.0K |
| Accounts payable | -$2.3M | -$1.3M |
| Accrued expenses and other current liabilities | $1.4M | -$4.0M |
| Deferred revenue | -$1.6M | $9.4M |
| Operating lease liabilities | -$1.3M | $11.6M |
| Other non-current assets | $270.0K | $340.0K |
| Net cash used in operating activities | -$78.6M | -$60.1M |
| Purchases of marketable securities | -$26.2M | -$146.3M |
| Proceeds from maturities of marketable securities | $70.7M | $40.9M |
| Purchases of property and equipment | -$518.0K | -$17.9M |
| Net cash provided by (used in) investing activities | $44.0M | -$123.3M |
| Proceeds from PIPE financing, net of issuance costs | $0 | $67.4M |
| Proceeds from exercises of stock options | $685.0K | $2.0M |
| Net cash provided by financing activities | $685.0K | $69.4M |
| Effect of exchange rate changes on cash, cash equivalents and restricted cash | $64.0K | -$4.0K |
| Net decrease in cash, cash equivalents and restricted cash | -$33.8M | -$114.1M |
| Property and equipment capitalized under tenant improvement allowance | $0 | $10.7M |
| Purchases of property and equipment in accounts payable and accrued expenses | $0 | $48.0K |
| Cash paid for income taxes | $1.0K | $141.0K |
| Cash paid for operating lease liabilities | $6.3M | $3.1M |
No quarter-by-quarter statement was filed.
Corporate structure
Korro Bio, Inc. sits at the top of its group. 1 entity, 1 country on record. Switch between the flow chart and the network, and select any entity to see its details.
Major holders of Korro Bio, Inc.
- BALYASNY ASSET MANAGEMENT L.P. Filed SCHEDULE 13G/A on Korro Bio, Inc., latest Aug 14, 2026
- Atlas Venture Fund XI, L.P. Filed SCHEDULE 13D/A on Korro Bio, Inc., latest Aug 4, 2026 (2 filings since Nov 13, 2023)
- BlackRock Filed SCHEDULE 13G on Korro Bio, Inc., latest Jul 29, 2026 (3 filings since Feb 3, 2022)
- Point72 Asset Management, L.P. Filed SCHEDULE 13G/A on Korro Bio, Inc., latest May 15, 2026 (6 filings since Nov 9, 2023)
- Lynx1 Capital Management LP Filed SCHEDULE 13G/A on Korro Bio, Inc., latest Apr 2, 2026 (2 filings since Jan 5, 2026)
- VANGUARD GROUP INC Filed SCHEDULE 13G/A on Korro Bio, Inc., latest Mar 27, 2026 (2 filings since Jan 30, 2026)
- Venrock Healthcare Capital Partners III, L.P. Filed SCHEDULE 13G on Korro Bio, Inc., latest Mar 17, 2026
- New Enterprise Associates 17, L.P. Filed SCHEDULE 13D/A on Korro Bio, Inc., latest Mar 12, 2026 (3 filings since Nov 17, 2023)
- DRIEHAUS CAPITAL MANAGEMENT LLC Filed SCHEDULE 13G/A on Korro Bio, Inc., latest Feb 17, 2026 (3 filings since Feb 14, 2025)
- Nantahala Capital Management, LLC Filed SCHEDULE 13G on Korro Bio, Inc., latest Feb 13, 2026
- FMR LLC Filed SCHEDULE 13G/A on Korro Bio, Inc., latest Feb 5, 2026 (3 filings since Feb 9, 2024)
- Deep Track Capital, LP Filed SCHEDULE 13G/A on Korro Bio, Inc., latest Aug 14, 2025 (3 filings since Apr 26, 2024)
- Korro Bio, Inc. Cambridge, Massachusetts
Built from major holders from Schedules 13D and 13G. Each entity in the chart links to its source.
What it owns
What Korro Bio, Inc. reports owning in its annual reports to the SEC: buildings, land and equipment, real estate and locations, investments, intangible assets and inventory, at the end of its latest fiscal year and a year before.
Property and equipment
| Item | Latest | A year before | Change |
|---|---|---|---|
| Property and equipment, before depreciation | $18.7M4 Dec 31, 2025 | $35.0M4 Dec 31, 2024 | −46.5% |
| Accumulated depreciation | $10.6M4 Dec 31, 2025 | $7.3M4 Dec 31, 2024 | +44.2% |
| Property and equipment, net | $8.2M4 Dec 31, 2025 | $27.7M4 Dec 31, 2024 | −70.5% |
| Operating-lease assets (leased space) | $8.1M4 Dec 31, 2025 | $23.8M4 Dec 31, 2024 | −66.2% |
Investments
| Item | Latest | A year before | Change |
|---|---|---|---|
| Cash and cash equivalents | $21.8M4 Dec 31, 2025 | $55.6M4 Dec 31, 2024 | −60.8% |
| Marketable securities, current | $53.3M4 Dec 31, 2025 | $70.5M4 Dec 31, 2024 | −24.3% |
| Marketable securities, non-current | $10.0M4 Dec 31, 2025 | $37.0M4 Dec 31, 2024 | −72.9% |
| Debt securities available for sale | $63.4M4 Dec 31, 2025 | $107.4M4 Dec 31, 2024 | −41.0% |
Properties, in its own words
Our principal office is located at 60 First Street, 2nd Floor, Suite 250, Cambridge, MA 02141, where we lease approximately 50,453 square feet of office and laboratory space. The lease term began in May 2023 and will end in April 2034 with an option to extend the term of the lease for an additional five years.
We believe that our existing office and laboratory space is adequate for our needs for the foreseeable future. If required, we believe that suitable additional or substitute space will be available in the future on commercially reasonable terms to accommodate any such expansion of our operations.
Item 2 of the 10-K filed Mar 12, 2026.3
Leadership
Who has led Korro Bio, Inc., and when. Pick a name to see everywhere that person has worked.
Chief executive
Chief financial officer
Chief operating officer
20202025
- Chief executive officerRam Aiyar Nov 7, 2023 to now12
- Chief executive officerDavid L. Lucchino Oct 2, 2019 to Aug 22, 202313
- PresidentRam Aiyar Nov 7, 2023 to now12
- PresidentDavid L. Lucchino Oct 2, 2019 to Aug 22, 202313
- Chief financial officerVineet Agarwal Nov 7, 2023 to Feb 5, 202514
- Chief financial officerPeter P. Pfreundschuh Dec 3, 2020 to Feb 23, 202215
- Chief operating officerTodd Chappell Nov 7, 2023 to now16
Board members and other officers (27)
- Senior Vice President, FinanceOliver Dolan Feb 11, 2025 to now17
- Chief Scientific OfficerLoic A. Vincent Apr 1, 2025 to now18
- Chief Medical OfficerOlukemi Olugemo May 14, 2024 to Feb 5, 202519
- OfficerShelby J. Walker Nov 7, 2023 to Nov 7, 202320
- Chief Scientific OfficerSteve Colletti Nov 7, 2023 to Nov 7, 202321
- Chief Manufacturing OfficerQuentin McCubbin Jan 26, 2021 to Jan 27, 202322
- Chief People OfficerWendy S. Arnold Feb 11, 2020 to Jan 27, 202323
- Chief Development OfficerCarl Lebel Oct 2, 2019 to Jan 27, 202324
- Chief Scientific OfficerChristopher R. Loose Oct 2, 2019 to Jul 31, 202325
- Chief Medical OfficerDana Charles Hilt Oct 2, 2019 to Apr 22, 202126
- VP Finance & OperationsRichard J. Mitrano Oct 2, 2019 to Aug 22, 202327
- Board memberKatharine Knobil Aug 28, 2024 to now28
- Board memberAli Behbahani Nov 7, 2023 to now29
- Board memberJean Francois Formela Nov 7, 2023 to now30
- Board memberNessan Bermingham Nov 7, 2023 to now31
- Board memberRam Aiyar Nov 7, 2023 to now12
- Board memberTimothy R. Pearson Nov 7, 2023 to now32
- Board memberRachel Meyers Nov 29, 2023 to now33
- Board memberCynthia L. Feldmann Sep 25, 2020 to Aug 19, 202234
- Board memberDavid L. Lucchino Oct 2, 2019 to Jun 12, 202413
- Board memberJoel S. Marcus Oct 2, 2019 to Aug 19, 202235
- Board memberMarc A. Cohen Oct 2, 2019 to Jun 23, 202236
- Board memberMichael Huang Oct 2, 2019 to Aug 19, 202237
- Board memberRobert S. Langer, Jr. Oct 2, 2019 to Aug 19, 202238
- Board memberTimothy J. Barberich Oct 2, 2019 to Aug 19, 202239
- General counselJeffrey Cerio Sep 3, 2024 to now40
- General counselMichael Bookman Jan 26, 2021 to Apr 22, 202141
Former names
- Frequency Therapeutics, Inc.Apr 14, 2017 to Nov 6, 20232
Timeline
- Oct 5, 20268-K Other events42
- Aug 19, 20268-K Other events43
- Aug 6, 20268-K Entered a material agreement; Results of operations; Unregistered sale of shares44
- Jun 11, 20268-K Shareholder vote45
- May 19, 20268-K Other events46
- May 7, 20268-K Results of operations47
- Mar 12, 20268-K Results of operations48
- Mar 9, 20268-K Entered a material agreement; Results of operations; Unregistered sale of shares49
- Jan 27, 20268-K Other events50
- Jan 15, 20268-K Other events51
- Dec 18, 20258-K Executive or director change52
- Nov 12, 20258-K Entered a material agreement; Results of operations; Exit or restructuring costs53
- Nov 7, 2023New chief executive Ram Aiyar becomes CEO12
- Oct 2, 2019New chief executive David L. Lucchino becomes CEO13
Calendar
Coming up
- Nov 11, 2026Reports results for the quarter ending Sep/2026 A year earlier it reported ($1.92) a share, on Nov 12, 2025.54
When it reported results
- Aug 6, 2026Reported quarterly or annual results44
- May 7, 2026Reported quarterly or annual results47
- Mar 12, 2026Reported quarterly or annual results48
- Mar 9, 2026Reported quarterly or annual results49
- Nov 12, 2025Reported quarterly or annual results53
- Aug 12, 2025Reported quarterly or annual results55
- May 7, 2025Reported quarterly or annual results56
- Mar 18, 2025Reported quarterly or annual results57
Upcoming dates from Nasdaq's calendar; past results from the company's 8-K filings (Item 2.02). The full markets calendar
Filings
615 filings to the SEC since October 2021: 6 annual reports, 15 quarterly reports, 68 major events, 219 insider forms, 49 large holders, 258 other. The latest 20:
- Oct 5, 20268-K EDGAR
- Sep 15, 20264 EDGAR
- Sep 14, 2026144 EDGAR
- Sep 14, 2026144 EDGAR
- Sep 14, 20264 EDGAR
- Sep 11, 2026144 EDGAR
- Sep 11, 2026144 EDGAR
- Sep 11, 2026144 EDGAR
- Sep 10, 20264 EDGAR
- Sep 9, 2026144 EDGAR
- Sep 8, 2026144 EDGAR
- Aug 28, 20264 EDGAR
- Aug 26, 2026144 EDGAR
- Aug 26, 2026144 EDGAR
- Aug 21, 20264 EDGAR
- Aug 19, 2026144 EDGAR
- Aug 19, 2026144 EDGAR
- Aug 19, 20268-K EDGAR
- Aug 14, 2026SCHEDULE 13G/A EDGAR
- Aug 13, 20264 EDGAR
The 615 filings since October 2021 can be filtered by form type and year here when JavaScript is on.
Every filing from the last five years, summarized. The full record is on SEC EDGAR.
Insider trades
168 open-market trades by officers, directors and large owners since October 2021: 22 buys and 146 sales. Grants, option exercises and gifts are left out.
| Date | Who | Trade | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|
| Sep 14, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 38,490 | $14.12 | $543.5K | Form 4 |
| Sep 11, 2026 | Dolan OliverSenior Vice President, Finance | Sale | 5 | $13.72 | $69 | Form 4 |
| Sep 11, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 10,200 | $13.99 | $142.7K | Form 4 |
| Sep 9, 2026 | Dolan OliverSenior Vice President, Finance | Sale | 6 | $13.60 | $82 | Form 4 |
| Sep 8, 2026 | Dolan OliverSenior Vice President, Finance | Sale | 7,347 | $13.51 | $99.3K | Form 4 |
| Aug 26, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 300 | $13.96 | $4.2K | Form 4 |
| Aug 19, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 28,468 | $14.00 | $398.6K | Form 4 |
| Aug 11, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 2,143 | $13.96 | $29.9K | Form 4 |
| Aug 10, 2026 | Lynx1 Capital Management LP10% owner | Buy | 1,462 | $13.19 | $19.3K | Form 4 |
| Aug 6, 2026 | Lynx1 Capital Management LP10% owner | Buy | 5,222 | $11.40 | $59.5K | Form 4 |
| Aug 4, 2026 | Aiyar RamPresident and CEO | Sale | 5,802 | $10.84 | $62.9K | Form 4 |
| Jul 6, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 9,323 | $13.96 | $130.1K | Form 4 |
| Jul 2, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 100,700 | $14.03 | $1.4M | Form 4 |
| Jun 24, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 48,438 | $14.61 | $707.5K | Form 4 |
| Jun 23, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 119,005 | $14.25 | $1.7M | Form 4 |
| Jun 22, 2026 | FORMELA JEAN FRANCOISDirector | Sale | 3,962 | $13.95 | $55.3K | Form 4 |
| Jun 16, 2026 | Chappell ToddChief Operating Officer | Sale | 3,168 | $10.83 | $34.3K | Form 4 |
| Jun 16, 2026 | Vincent Loic AChief Scientific Officer | Sale | 3,418 | $10.83 | $37.0K | Form 4 |
| Jun 16, 2026 | Cerio JeffreyGeneral Counsel | Sale | 6,609 | $10.83 | $71.6K | Form 4 |
| Jun 16, 2026 | Dolan OliverSenior Vice President, Finance | Sale | 3,383 | $10.83 | $36.6K | Form 4 |
All 168 trades can be filtered by person here when JavaScript is on.
From Forms 4 filed with the SEC.
Major holders
Investors who own more than 5% of the shares must tell the SEC: a 13D if they may seek to influence the company, a 13G if they hold passively.
- BALYASNY ASSET MANAGEMENT L.P.SCHEDULE 13G/A, 1 filing Aug 14, 202658
- Atlas Venture Fund XI, L.P.SCHEDULE 13D/A, 2 filings Nov 13, 2023 to Aug 4, 202659
- BlackRockSCHEDULE 13G, 3 filings Feb 3, 2022 to Jul 29, 202660
- Point72 Asset Management, L.P.SCHEDULE 13G/A, 6 filings Nov 9, 2023 to May 15, 202661
- Lynx1 Capital Management LPSCHEDULE 13G/A, 2 filings Jan 5, 2026 to Apr 2, 202662
- VANGUARD GROUP INCSCHEDULE 13G/A, 2 filings Jan 30, 2026 to Mar 27, 202663
- Venrock Healthcare Capital Partners III, L.P.SCHEDULE 13G, 1 filing Mar 17, 202664
- New Enterprise Associates 17, L.P.SCHEDULE 13D/A, 3 filings Nov 17, 2023 to Mar 12, 202665
- DRIEHAUS CAPITAL MANAGEMENT LLCSCHEDULE 13G/A, 3 filings Feb 14, 2025 to Feb 17, 202666
- Nantahala Capital Management, LLCSCHEDULE 13G, 1 filing Feb 13, 202667
- FMR LLCSCHEDULE 13G/A, 3 filings Feb 9, 2024 to Feb 5, 202668
- Deep Track Capital, LPSCHEDULE 13G/A, 3 filings Apr 26, 2024 to Aug 14, 202569
- AllianceBernsteinSCHEDULE 13G/A, 2 filings Feb 5, 2025 to Aug 13, 202570
- CITADEL ADVISORS LLCSCHEDULE 13G/A, 3 filings Nov 13, 2023 to Feb 14, 202571
- Cormorant Asset Management, LPSC 13G/A, 3 filings Nov 16, 2023 to Nov 14, 202472
- EVENTIDE ASSET MANAGEMENT, LLCSC 13G/A, 2 filings Feb 14, 2024 to Nov 14, 202473
- Artal International S.C.A.SC 13G/A, 2 filings Nov 13, 2023 to Jul 12, 202474
- Platanus Investment LLCSC 13G, 1 filing Nov 17, 202375
- David L. LucchinoSC 13G, 1 filing Oct 12, 202376
- Federated HermesSC 13G/A, 2 filings Feb 14, 2022 to Jun 10, 202277
- WASATCH ADVISORS LPSC 13G/A, 2 filings Feb 11, 2022 to Jun 6, 202278
- PERCEPTIVE ADVISORS LLCSC 13G/A, 1 filing Feb 14, 202279
Executive pay
What the company paid its top executives, from the summary compensation table in its proxy statement. Total pay includes salary, bonus, stock and option awards and other pay, as the company valued them.
| Year | Executive | Age | Salary | Total pay |
|---|---|---|---|---|
| 2025 | Ram Aiyar | $633.2K | $3.1M80 | |
| 2025 | Kemi Olugemo | $424.7K | $2.3M80 | |
| 2025 | Vineet Agarwal | $375.3K | $1.7M80 | |
| 2025 | Jeffrey Cerio | $425.0K | $1.6M80 | |
| 2025 | Chief Scientific Officer | $361.8K | $1.6M80 | |
| 2024 | Former Chief Medical Officer | $292.7K | $2.7M80 | |
| 2024 | Senior Vice PresidentGeneral Counsel and Corporate Secretary | $138.2K | $1.5M80 | |
| 2024 | Chief Executive OfficerPresident and Interim Chief Financial Officer | $610.0K | $939.1K80 | |
| 2024 | Former Chief Financial Officer | $440.0K | $617.5K80 |
Held by these funds
The largest holders among investment managers' 13F reports for the quarter ending Jun 30, 2026, the top 25 of 100. Change is in shares since the quarter before.
13F reports cover disclosed long positions in U.S. stocks only.
SEC filer profile
How Korro Bio, Inc. is registered with the Securities and Exchange Commission, from its EDGAR record and the cover page of its latest annual report.
- Name on EDGARKorro Bio, Inc.1
- CIK0001703647
- Employer ID (EIN)47-23244503
- Filer statusNon-accelerated filer not an emerging growth company; a smaller reporting company; not a shell company3
- Incorporated inDelaware3
- Fiscal year endsDecember 311
- Industry code (SIC)2834 Pharmaceutical Preparations1
- SEC reviewing officeOffice of Life Sciences, Division of Corporation Finance1
- Business address60 First Street, 2Nd Floor, Suite 250, Cambridge, MA 021411
- Phone617-468-19991
- Shares outstanding14,725,646 as of Aug 5, 202611
- Public float$89.0M as of Jun 30, 20253
- AuditorErnst & Young LLP, Boston, Massachusetts PCAOB ID 42; no auditor attestation of internal control over financial reporting3
- On EDGAR sinceApr 14, 20171
- Filings825 in all: 4 (297), 144 (166), 8-K (92), 3 (46), 424B3 (27), 10-Q (21), SC 13G/A (19), SC 13G (16)1
All 43 form types
CORRESP (15), SCHEDULE 13G/A (12), EFFECT (11), UPLOAD (11), SCHEDULE 13G (8), 10-K (7), 4/A (7), DEFA14A (7), 425 (6), DEF 14A (6), S-8 (6), S-3 (4), 424B5 (3), ARS (3), D (3), POS AM (3), S-1 (3), S-1/A (3), S-4/A (3), 5 (2), SC 13D (2), SCHEDULE 13D/A (2), SEC STAFF LETTER (2), 10-K/A (1), 144/A (1), 424B4 (1), 8-A12B (1), 8-K/A (1), CERT (1), DRS (1), DRS/A (1), DRSLTR (1), PRE 14A (1), S-4 (1), SC 13D/A (1)
- Latest filingsAnnual report (10-K) Mar 12, 2026
Quarterly report (10-Q) Aug 6, 2026
Proxy statement (DEF 14A) Apr 16, 2026
Latest 8-K (8-K) Oct 5, 2026
Securities registered for trading
| Class | Symbol | Exchange |
|---|---|---|
| Common stock, par value $0.001 per share | KRRO | Nasdaq |
From the cover page of the 10-K filed Mar 12, 2026 (Section 12(b) of the Exchange Act).3
Risk factors and legal proceedings
The risks Korro Bio, Inc. names in Item 1A of its 10-K filed Mar 12, 2026: 73 risks under these headings, as written.3
- Risks Related to Our Business
- We have incurred significant losses since inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.
- We have never generated revenue from product sales and may never become profitable.
- We will need substantial additional funding. If we are unable to raise capital when needed, we will be forced to delay, reduce, eliminate or prioritize among our research and development programs or future commercialization efforts.
- We did not reach projected levels of protein in patients in our Phase 1/2a REWRITE clinical trial of KRRO-110 for AATD and have transitioned to GalNAc-conjugated delivery for our AATD program, and may experience delays in developing a potential treatment for AATD. We have not completed any clinical trials nor reported any clinical trial results for any of our proposed delivery methods or RNA editing approaches. Any favorable results we may have from our earlier preclinical studies may not be predictive of results that may be observed in later preclinical studies or clinical trials.
- If preclinical studies or clinical trials of any lead candidate or development candidate we may identify fail to demonstrate safety and efficacy to the satisfaction of regulatory authorities or do not otherwise produce positive results, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of such development candidate.
- Our business is substantially dependent on the success of KRRO-121, our lead development candidate, and if KRRO-121 fails to advance successfully, our business would be materially and adversely affected.
- If we experience delays or difficulties in the enrollment of patients in clinical trials, or other delays in our clinical trials, our receipt of necessary regulatory approvals could be delayed or prevented.
- Risks Related to Discovery, Development and Commercialization
- The gene editing field and RNA editing in particular is relatively new and is evolving rapidly. We are very early in our development efforts and may not be successful in identifying and developing any candidates. It will be many years before we or our collaborators commercialize a development candidate or generate any revenues, if ever. Additionally, other genetic medicine technologies may be discovered that provide significant advantages over RNA editing, which could materially harm our business.
- RNA editing is a novel technology with limited clinical validation for human therapeutic use. The approaches we take to discover and develop novel therapeutics are unproven and may never lead to marketable products.
- We are very early in our development efforts, and our preclinical studies and clinical trials may not be successful. If we are unable to commercialize our development candidates or experience significant delays in doing so, our business will be materially harmed.
The other 63 risks
- Any development candidates we develop may fail in preclinical or clinical development or be delayed to a point where they do not become commercially viable.
- We may not be able to conduct clinical trials successfully due to various process-related factors that could negatively impact our business plans.
- If we cannot successfully manufacture our development candidates for our research and development and preclinical activities, or manufacture sufficient amounts of our development candidates to meet our clinical requirements and timelines, our business may be materially harmed.
- The process of manufacturing oligonucleotides is complex and we may encounter difficulties in production, particularly with respect to process development or scaling-up of our manufacturing capabilities.
- We may expend our limited resources to pursue a particular development candidate or indication and fail to capitalize on development candidates or indications that may be more profitable or for which there is a greater likelihood of success.
- Our development candidates may cause undesirable and unforeseen side effects or be perceived by the public as unsafe, which could delay or prevent their advancement into clinical trials or regulatory approval, limit the commercial potential or result in significant negative consequences.
- If we are unable to successfully identify patients who are likely to benefit from therapy with any development candidates we develop, or experience significant delays in doing so, we may not realize the full commercial potential of any products we may develop.
- If we are unable to establish sales and marketing capabilities or enter into agreements with third parties to market and sell any development candidates, we may be unable to generate any revenues.
- Even if we receive regulatory approval to market our development candidates, the market may not be receptive to our development candidates upon their commercial introduction, which will prevent us from becoming profitable.
- The pharmaceutical industry is intensely competitive. If we are unable to compete effectively with existing drugs, new treatment methods and new technologies, we may be unable to commercialize successfully any drugs that we develop.
- Healthcare legislative or regulatory reform measures may have a negative impact on our business and results of operations.
- If the market opportunities for any development candidates we may develop are smaller than we believe they are, our potential revenues may be adversely affected, and our business may suffer.
- While we intend to seek designations for our development candidates with the FDA and comparable foreign regulatory authorities that are intended to confer benefits such as a faster development process or an accelerated regulatory pathway, there can be no assurance that we will successfully obtain such designations. In addition, even if one or more of our development candidates are granted such designations, we may not be able to realize the intended benefits of such designations.
- Risks Related to Regulatory, Legal, and Clinical Trials
- Because we are developing oligonucleotides, which are considered a relatively new class of drugs, there is increased risk that the outcome of our clinical trials will not be sufficient to obtain regulatory approval.
- Because we are developing development candidates in the field of genetic medicines in which there is little clinical experience, there is increased risk that the FDA, the EMA, HREC, TGA or other regulatory authorities may not consider the endpoints of our clinical trials to provide clinically meaningful results and that these results may be difficult to analyze.
- Even if we complete the necessary preclinical studies and clinical trials, we cannot predict when, or if, we will obtain regulatory approval to commercialize a development candidate and the approval may be for a narrower indication than we seek.
- We may be unable to obtain regulatory approval in the United States or foreign jurisdictions and, as a result, be unable to commercialize our development candidates and our ability to generate revenue will be materially impaired.
- Any development candidates for which we obtain marketing approval will be subject to extensive post-marketing regulatory requirements and could be subject to post-marketing restrictions or withdrawal from the market, and we may be subject to penalties if we fail to comply with regulatory requirements or if we experience unanticipated problems with our development candidates, when and if any of them are approved.
- Even if we obtain regulatory approvals, our marketed drugs will be subject to ongoing regulatory oversight. If we fail to comply with continuing U.S. and foreign requirements, our approvals, if obtained, could be limited or withdrawn, we could be subject to other penalties, and our business would be seriously harmed.
- The insurance coverage and reimbursement status of newly-approved products is uncertain. Failure to obtain or maintain adequate coverage and reimbursement for our development candidates could limit our product revenues.
- We may not be able to obtain orphan drug exclusivity for one or more of our development candidates, and even if we do, that exclusivity may not prevent the FDA or the EMA from approving other competing products.
- If we do not comply with laws regulating the protection of the environment and health and human safety, our business could be adversely affected.
- If we or our collaborators, manufacturers, service providers or other third parties fail to comply with applicable healthcare laws and regulations, we could be subject to enforcement actions, which could affect our ability to develop, market and sell our products and may harm our reputation.
- Our employees, consultants and collaborators may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.
- Product liability lawsuits against us could cause us to incur substantial liabilities and could limit commercialization of any medicines that we may develop.
- Our internal computer and information systems, or those used by our CROs, CMOs or other contractors or consultants, may fail or suffer security breaches, which could result in a material disruption of our development programs.
- We may be unable to adequately protect our information systems from cybersecurity incidents or data breaches, which could result in the disclosure of confidential information, damage our reputation, and subject us to significant financial and legal exposure.
- Our failure to obtain regulatory approval in international jurisdictions would prevent us from marketing our development candidates outside the United States.
- Disruptions at the FDA, SEC and other government agencies caused by staffing cuts, funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved, or commercialized in a timely manner or at all, which could negatively impact our business.
- We, our collaborators and our service providers may be subject to a variety of privacy and data security laws, regulations and contractual obligations, and our failure to comply with them could harm our business.
- The use of new and evolving technologies, such as artificial intelligence, or AI, in our offerings may result in spending material resources and presents risks and challenges that can impact our business including by posing security and other risks to our confidential information, proprietary information and personal information, and as a result we may be exposed to reputational harm and liability.
- Risks Related to Our Third Party Relationships
- We may be subject to claims that we or our employees or consultants have wrongfully used or disclosed alleged trade secrets of employees’ or consultants’ former employers or their clients. These claims may be costly to defend and if we do not successfully do so, we may be required to pay monetary damages and may lose valuable intellectual property rights or personnel.
- We expect to rely on third parties to conduct our clinical trials and some aspects of our research, as well as some aspects of our delivery methods, and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of such trials, research or testing.
- We may not be successful in finding strategic collaborators for continuing development of certain of our development candidates or successfully commercializing or competing in the market for certain indications; and we may not see any benefit from our collaboration agreement with Novo Nordisk, which is currently on hold.
- Future acquisitions or strategic alliances could disrupt our business and harm our financial condition and results of operations.
- We rely, and anticipate that we will rely, on third parties to design, conduct, supervise and monitor our preclinical studies and clinical trials, and if those third parties perform in an unsatisfactory manner, it may harm our business.
- We rely on third parties in the supply and manufacture of our lead candidates and development candidates for our research, preclinical and clinical activities, and may do the same for commercial supplies of our lead or development candidates.
- Risks Related to Our Personnel, Operations and Growth
- If we are unable to attract and retain qualified key management and scientists, staff, consultants and advisors, our ability to implement our business plan may be adversely affected.
- We expect to need to expand our research, development, delivery, manufacturing, commercialization, regulatory and future sales and marketing capabilities over time, and as a result, we may encounter difficulties in managing our future growth, which could disrupt our operations.
- Risks Related to Intellectual Property
- If we are not able to obtain or protect intellectual property rights related to any of our lead candidates and development candidates, development and commercialization of our development candidates may be adversely affected.
- Our pending patent applications may not issue as patents, and even issued patents may not provide sufficient protection of our RNA editing platform OPERA, our lead candidates and our development candidates.
- We may not identify relevant third-party patents or may incorrectly interpret the relevance, scope or expiration of a third-party patent, which might adversely affect our ability to develop and market our development candidates.
- We may be involved in lawsuits to protect or enforce our patents, which could be expensive, time consuming and unsuccessful.
- Third-party claims of intellectual property infringement may prevent, delay or otherwise interfere with our product discovery and development efforts.
- We may not be successful in acquiring or in-licensing necessary rights to key technologies or any development candidates we may develop.
- We may become subject to claims challenging the inventorship or ownership of our patents and other intellectual property.
- Third parties may assert that our employees, consultants, or advisors have wrongfully used or disclosed confidential information or misappropriated trade secrets.
- Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment, and other requirements imposed by government patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.
- We have limited foreign intellectual property rights and may not be able to protect our intellectual property and proprietary rights throughout the world.
- Changes in patent law in the United States and in non-U.S. jurisdictions could diminish the value of patents in general, thereby impairing our ability to protect our RNA editing platform technology, lead candidates and development candidates.
- If we are unable to protect the confidentiality of our trade secrets, our business and competitive position would be harmed.
- Patent terms may be inadequate to protect our competitive position on our development candidates for an adequate amount of time.
- If we do not obtain PTE and data exclusivity for any development candidates we may develop, our business may be materially harmed.
- Intellectual property rights do not necessarily address all potential threats.
- Our use of open source software could impose limitations on our ability to commercialize our development candidates.
- If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interest and our business may be adversely affected.
- General Risk Factors
- Our business could be materially and adversely affected in the future by the effects of disease outbreaks, epidemics and pandemics.
- Our operations are vulnerable to interruption by disasters, terrorist activity, pandemics and other events beyond our control, which could harm our business.
- Litigation costs and the outcome of litigation could have a material adverse effect on our business.
- The price of our common stock is volatile and fluctuates substantially, which could result in substantial losses for our stockholders.
- We are incurring and expect to continue to incur additional costs and increased demands upon management as a result of complying with the laws and regulations affecting public companies.
- Once we are no longer a smaller reporting company or otherwise no longer qualify for applicable exemptions, we will be subject to additional laws and regulations affecting public companies that will increase our costs and the demands on management and could harm our operating results and cash flows.
- If we fail to maintain proper and effective internal controls, our ability to produce accurate financial statements on a timely basis could be impaired.
Legal proceedings
From time to time, we may be involved in various other claims and legal proceedings relating to claims arising out of our operations. We are not currently a party to any material legal proceedings.
The opening of Item 3, Legal Proceedings.3
Sources
The numbers on this page point here. Each one links to the record it came from.
- 1SEC EDGARKorro Bio, Inc. filings on SEC EDGAR
- 2SEC EDGARKorro Bio, Inc. filings on SEC EDGAR
- 3
- 4SEC EDGARKorro Bio, Inc. 10-K for fiscal 2025
- 5SEC EDGARKorro Bio, Inc. 10-K for fiscal 2019
- 6SEC EDGARKorro Bio, Inc. 10-K for fiscal 2020
- 7SEC EDGARKorro Bio, Inc. 10-K for fiscal 2021
- 8SEC EDGARKorro Bio, Inc. 10-K for fiscal 2023
- 9SEC EDGARKorro Bio, Inc. 10-K for fiscal 2022
- 10SEC EDGARKorro Bio, Inc. 10-Q for fiscal 2026
- 11SEC EDGARKorro Bio, Inc. 10-Q for fiscal 2026
- 12SEC EDGARRam Aiyar, Chief executive officer
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- 20SEC EDGARShelby J. Walker, Officer
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- 28SEC EDGARKatharine Knobil, Board member
- 29SEC EDGARAli Behbahani, Board member
- 30SEC EDGARJean Francois Formela, Board member
- 31SEC EDGARNessan Bermingham, Board member
- 32SEC EDGARTimothy R. Pearson, Board member
- 33SEC EDGARRachel Meyers, Board member
- 34SEC EDGARCynthia L. Feldmann, Board member
- 35SEC EDGARJoel S. Marcus, Board member
- 36SEC EDGARMarc A. Cohen, Board member
- 37SEC EDGARMichael Huang, Board member
- 38SEC EDGARRobert S. Langer, Jr., Board member
- 39SEC EDGARTimothy J. Barberich, Board member
- 40SEC EDGARJeffrey Cerio, General counsel
- 41SEC EDGARMichael Bookman, General counsel
- 42SEC EDGAROther events
- 43SEC EDGAROther events
- 44
- 45SEC EDGARShareholder vote
- 46SEC EDGAROther events
- 47SEC EDGARResults of operations
- 48SEC EDGARResults of operations
- 49
- 50SEC EDGAROther events
- 51SEC EDGAROther events
- 52SEC EDGARExecutive or director change
- 53
- 54NasdaqNasdaq calendar
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