undamentalytics Newsletter
Sign in

Korro Bio, Inc. (KRRO) stock

Add to watchlist

Add holding +

NASDAQ: KRRO Nasdaq Biotechnology Next results ~November 12, 2026

E Fundamentals grade

Korro Bio, Inc. is a US-listed company in the biotechnology industry. Its financial year ends in December.

Stock price today

Loading chart…

Third-party market data · may be delayed

Model estimate per share

~$6.4

Growth cash-flow model

Base case. Range ~$6.3–$6.4. Revenue for this year and next from analysts' consensus, then growth fading to 2.5%; the operating margin moving to profitable peers'; investment needed per dollar of growth from peers; reduced by a failure probability.

Price vs value

No Buy/Hold/Sell rating is issued: valued with our growth model, which doesn't carry a Buy/Hold/Sell rating yet.

Korro Bio, Inc. valuation: adjust assumptions and compare models →

Who’s trading

What company insiders, investment funds and members of Congress have been doing with the stock, from their own filings.

  • Insiders11 buying, 6 selling16 purchases and 33 sales by directors and officers, last 12 monthsInsider trades
  • Funds67 adding, 30 cuttingOf 22 active managers that changed their stake, 13 added; quarter to June 30, 2026Fund buyers and sellers

Value diary

Our note on each quarter Korro Bio files

Where Korro Bio stands after its latest 10-Q

Korro Bio has little or no product revenue yet; it used $68m of cash in the twelve months to June 2026. The diluted share count is up 28.2% on a year earlier, which dilutes existing holders. It passes 2 of our 2 financial-health checks.

Source: 10-Q filed August 6, 2026 on SEC EDGAR · Financials · Valuation

Written from the company's filings and our models when each quarter's report arrives. Figures in older notes are as published at the time. Not investment advice.

The Fundamentalytics view

Next results ~November 12, 2026 (estimated)

Korro Bio, Inc.'s trailing-twelve-month revenue fell 62.1% year on year, with a free-cash-flow margin of -2865.9%. Where it lags: net margin of -4477.1% ranks 163 of 180 biotechnology companies we cover.

Current signal Free cash flow diverging from earnings: TTM free cash flow grew 7.6% while net income fell 16.7%: a 24pp divergence.

Assembled from SEC-filed figures — the full workings are on this page and in our methodology. Observations, not recommendations.

Highlights

How we pick these

Strengths

  • Net cash. Cash exceeds long-term debt by $0.0bn.
  • Beating expectations. Earnings per share beat the analysts' consensus estimate in each of the last four quarters.

Things to watch

  • Results due soon. Results are expected around 6 November; the share price can move sharply on the day.
  • Revenue shrinking. Revenue fell 62.1% over the last 12 months.
  • Growth slowing. The growth rate is 41.8 points lower than a quarter earlier.
  • Loss-making. Operating margin is -4625.5%: costs exceed revenue.
  • Margins narrowing. Operating margin is down 3056.4 points on a year ago.
  • Burning cash. Free cash flow was -2865.9% of revenue over the last 12 months.

Latest results: FY2026 Q2

Filed August 6, 2026
Earnings per share
-$1.07 against an average estimate of -$1.28: beat by 16.3%
Share reaction
+15.2% in the first session after the results on August 6, 2026, against +0.5% for the S&P 500
Next report
November 12, 2026; average EPS estimate -$1.26

Korro Bio's figures from its SEC filings and results release; estimates are the analysts' average. Not a recommendation.

Price chart

  • 1 day+10.7%
  • 1 week+31.8%
  • 1 month+64.4%
  • This year+97.8%
  • 1 year-61.3%
  • 5 years-95.5%
  • S&P 500 this year+11.2%

Closing prices to 2026-11-02. Price change only, dividends excluded.

Loading chart…

Third-party market data · may be delayed

At a glance

Trailing twelve months, from SEC filings

Profitability

Revenue (TTM)
$2.4M
Operating margin
-4625.5%
Net margin
-4477.1%
EPS (TTM, diluted)
$-8.88

Growth

Revenue growth
−62.1%
Change in growth rate
−41.8 pts
Share count change
+28.2%

Cash

Free cash flow (TTM)
-$68.3M
FCF margin
-2865.9%
Stock pay % of revenue
391.7%

Earnings

Last results
August 6, 2026
Next results (est.)
November 6, 2026

News & updates

Updated October 31, 2026

Company announcements, filed results and changes that matter to shareholders.

  1. Announcement
  2. Announcement
  3. Announcement
  4. Results

Refreshed hourly when new source data is available. Summaries are checked against company releases and SEC filings. Company announcement headlines are labelled when a checked summary is unavailable.

Valuation

Korro Bio, Inc. valuation models and calculator

Fundamentalytics rating

model v1.6 · 2026-11-03

Not rated: valued with our growth model, which doesn't carry a Buy/Hold/Sell rating yet.

Valuation models

We value Korro Bio, Inc. as an operating company, with every model that fits that kind of business. Cost of equity 12.1%: the 10-year Treasury yield (4.9%) plus a beta of 1.59 times a 4.5% equity risk premium.

Value per share by model
Model Value per share In the combined value?
Growth cash-flow model Revenue for this year and next from analysts' consensus, then growth fading to 2.5%; the operating margin moving to profitable peers'; investment needed per dollar of growth from peers; reduced by a failure probability. For young or fast-growing companies. The starting margin is normalized to between -100% and 60%; net margin is a proxy when operating income is not tagged. Uses analysts' consensus estimates (third-party data), not our forecasts. ~$6.4 ~$6.3–$6.4 Primary model, counts double
Price-to-earnings vs peers Earnings per share times peers' typical (harmonic-mean) price-to-earnings. — Does not apply: no positive earnings in the latest twelve months
Residual income Book value plus the present value of returns above the cost of equity, fading over ten years. — Does not apply: the model gives no positive value
Justified price-to-book Book value times (return on equity - growth) / (cost of equity - growth): steady-state returns. — Does not apply: return on equity is not positive
Forward price-to-sales vs peers Next year's consensus sales per share times peers' typical forward price-to-sales; only when earnings are negative. Uses analysts' consensus estimates (third-party data), not our forecasts. ~$0.1 ~$0.1–$0.5 Left out: out of range vs price (0.01x)
Revenue-to-maturity model Revenue grown to maturity with the cash margin moving to the industry's; for companies not yet profitable. — Does not apply: revenue and margins don't support a positive value
Combined value Weighted average of the models that apply: the primary model (growth cash-flow model) counts double. Models more than 5x or less than 0.2x the share price, or more than 3x away from the other models' median, are left out. ~$6.4 ~$6.3–$6.4 1 model

Different models fail in different ways, so where several apply we average them rather than trust one. Peer-based models compare Korro Bio, Inc. with Biotechnology in our coverage, using third-party market data. Model values are estimates under stated assumptions, updated as new filings arrive; not price targets or investment advice. How each model works.

Valuation multiples over time Market data may be delayed

At fiscal year end 2019202020212022202320242025Now
Share price$876.50$1763.00$256.50$192.50$47.93$38.07$8.01$15.85
Market value$152m$1.1bn$176m$49m$73m$340m$75m$190m
+ Net debt (− = net cash)−$200m−$220m−$79m−$26m−$166m−$56m−$22m−$25m
Enterprise value−$48m$917m$97m$23m−$93m$284m$53m$165m
Multiples
Price / sales 5.2x30.7x12.5x——149.5x11.8x79.9x
Price / earnings ————————
Price / free cash flow 4.6x———————
EV / EBITDA ————————

Market value uses the period's diluted share count; figures for each fiscal year use that year's results and the price at year end. "Now" uses today's price and the last twelve months.

Moat

Not assessed: fewer than five years of comparable figures in the filings. AI disruption exposure for this industry: Medium.

A rules-based reading of reported figures, not a forecast and not investment advice. How the score is built: methodology.

Forecasts and guidance

Next results: November 12, 2026, before the open. Analysts expect revenue of $187500 and EPS of −$1.26 (range −$2.04 to −$0.93) for the quarter.

Analysts' consensus

Fiscal yearEPSGrowthRevenueGrowth
Current −$5.23 +41% $375000 −94%
Next −$4.42 +16% $587500 +57%

How the EPS forecast has moved

The consensus EPS forecast for the current fiscal year is +1.1% on 90 days ago. In the last 30 days, 0 analysts raised Korro Bio, Inc.'s forecast and 1 cut it.

Consensus EPS forecast Korro Bio, Inc., last 90 days
−$6.00 −$4.00 −$2.00 $0.00 90 days ago 60 days ago 30 days ago 7 days ago Now Current fiscal year, 90 days ago: −$5.18 Current fiscal year, 60 days ago: −$5.18 Current fiscal year, 30 days ago: −$5.18 Current fiscal year, 7 days ago: −$5.23 Current fiscal year, Now: −$5.23 −$5.23 Next fiscal year, 90 days ago: −$5.04 Next fiscal year, 60 days ago: −$4.46 Next fiscal year, 30 days ago: −$4.46 Next fiscal year, 7 days ago: −$4.42 Next fiscal year, Now: −$4.42 −$4.42

Average of analysts' published estimates (third-party data).

View chart data
Period Current fiscal yearNext fiscal year
90 days ago −$5.18−$5.04
60 days ago −$5.18−$4.46
30 days ago −$5.18−$4.46
7 days ago −$5.23−$4.42
Now −$5.23−$4.42

Earnings against estimates

Quarter toEstimateActualSurprise
Jun 2026 −$1.28 −$1.07 +16.3%
Mar 2026 −$1.98 −$1.69 +14.7%
Dec 2025 −$2.14 −$1.65 +22.9%
Sept 2025 −$2.68 −$1.92 +28.3%

Adjusted EPS as companies report it, against the average analyst estimate.

Management guidance

Earnings release, August 6, 2026

No numeric guidance in Korro Bio, Inc.'s latest earnings release (filed August 6, 2026). Some companies give their outlook only on the earnings call.

Analyst recommendations

10 analysts, Oct 2026
Buy990%
Hold110%
Sell00%

Monthly trend

  1. Oct 202618110
  2. Sep 202628111

Counts of recommendations published by analysts covering Korro Bio, Inc., by month. Source: Aggregated broker recommendations (third-party data). Aggregated counts only: we do not reproduce any firm's recommendation or price target, and these are not Fundamentalytics ratings.

Positioning

Short interest
13.2%
of tradable shares
Days to cover
7.94
at average volume
Short interest, 1 month
+12%
to October 15, 2026
Held by institutions
—
of shares
Held by insiders
0.9%
of shares
Employees
57
full time

Consensus figures average analysts' published estimates (third-party data); guidance is the company's own. Neither is our forecast. Short interest is reported twice a month and lags. Market data may be delayed.

This section is general information, not investment advice or a personal recommendation, and it does not take account of your objectives or circumstances. Forecasts and guidance are estimates, not promises: companies miss their own guidance and analysts' figures are often revised. Prices can fall as well as rise, and you can lose money. See our disclaimer.

Share-price performance

Market data may be delayed

What moved the share price

Last 12 months −61.3%

$40.91 on October 31, 2025 to $15.85

ThenNowEffect
Revenue (last 12 months) $6m $2m −62.1%
P/S multiple 61.0x 79.9x +31.0%
Share count 9m 12m −22.0%

Biggest factor: revenue. Loss-making at one end, so the split uses price/sales.

The effects multiply back to the price change exactly. Results are the last 12 months as known on each date (filings assumed public 45 days after quarter end).

Return and risk by year

Calendar year 202120222023202420252026 to date
Return
KRRO−86%−25%−75%−21%−79%+98%
Industry peers (median)−35%−57%−17%−29%−5%−27%
S&P 500+29%−18%+26%+25%+18%+11%
Months that ended higher
KRRO42%50%33%42%50%46%
S&P 50075%42%67%75%75%46%
Largest fall from a high during the year
KRRO−91%−82%−96%−65%−90%−42%
S&P 500−5%−25%−10%−8%−19%−9%

Worst fall since October 3, 2019: 100% from February 19, 2021 to December 2, 2025. Getting back needed a 51993% gain, and the shares have not yet recovered.

Price behaviour

52-week range
$5.28 – $36.82
From 52-week high
−57.0%
vs 50-day average
+38.3%
vs 200-day average
+32.4%
Volatility (1 year)
119%
Beta vs S&P 500
2.32

Volatility is the annualised standard deviation of daily returns. Beta 1.5 means the shares typically moved 1.5% for each 1% move in the S&P 500 over the past year. Prices to November 2, 2026.

Share price after results

Next day
8 up, 4 down
typical move ±17.8%
After a week
6 up, 6 down
typical move ±20.3%
After a month
5 up, 7 down
typical move ±33.6%
Results releasedNext dayS&P 500 next day5 days21 days
August 6, 2026 +15.2% +0.5% +15.6% +6.4%
May 7, 2026 −9.7% +0.5% −16.9% −20.6%
March 12, 2026 +8.8% −2.1% −6.0% +16.4%
March 9, 2026 +2.7% +0.7% +12.7% +20.4%
November 12, 2025 −80.2% −1.6% −80.5% −74.9%
August 12, 2025 +25.8% +1.4% +27.2% +128.5%
May 7, 2025 +4.1% +1.1% −4.6% −1.4%
March 18, 2025 −5.3% 0.0% −18.7% −46.3%
November 12, 2024 −25.2% −0.3% −36.6% −40.2%
August 13, 2024 +10.4% +2.0% +17.6% +12.4%
May 14, 2024 +5.0% +1.7% +1.1% −15.4%
March 26, 2024 +20.6% +0.7% +6.2% −20.3%

From the close before the release date to the close 1, 5 and 21 trading days after it, so releases before the open and after the close are both captured. Past moves don't predict future ones.

Korro Bio, Inc. in five measures

Fundamentals grade E
Growth Profitability Cash Balance sheet

Growth, profitability, cash generation and balance sheet are percentiles against the companies we cover in the same industry, from SEC filings (100 = best). Value compares the share price with our modelled value range (50 = at our base value; higher = cheaper). A description of reported data and our model — not a quality score or advice.

Fundamentals

Revenue (TTM) Korro Bio, Inc.
$0 $5M $10M $15M FY21 Q4 FY22 Q3 FY25 Q1 FY26 Q2 Revenue (TTM), FY21 Q4: $14.1M Revenue (TTM), FY22 Q1: $9.4M Revenue (TTM), FY22 Q2: $0 Revenue (TTM), FY22 Q3: $0 Revenue (TTM), FY22 Q4: $0 Revenue (TTM), FY24 Q4: $2.3M Revenue (TTM), FY25 Q1: $4.8M Revenue (TTM), FY25 Q2: $6.3M Revenue (TTM), FY25 Q3: $7.4M Revenue (TTM), FY25 Q4: $6.4M Revenue (TTM), FY26 Q1: $3.8M Revenue (TTM), FY26 Q2: $2.4M $2.4M

Source: SEC EDGAR filings. Retrieved October 29, 2026.

View chart data
Period Revenue (TTM)
FY21 Q4 $14.1M
FY22 Q1 $9.4M
FY22 Q2 $0
FY22 Q3 $0
FY22 Q4 $0
FY24 Q4 $2.3M
FY25 Q1 $4.8M
FY25 Q2 $6.3M
FY25 Q3 $7.4M
FY25 Q4 $6.4M
FY26 Q1 $3.8M
FY26 Q2 $2.4M
Revenue growth, TTM YoY Korro Bio, Inc.
-100% 0% 100% 200% FY21 Q2 FY21 Q4 FY22 Q2 FY22 Q4 FY26 Q2 Revenue growth, TTM YoY, FY21 Q2: -21.2% Revenue growth, TTM YoY, FY21 Q3: -24.3% Revenue growth, TTM YoY, FY21 Q4: -62.0% Revenue growth, TTM YoY, FY22 Q1: -72.6% Revenue growth, TTM YoY, FY22 Q2: -100.0% Revenue growth, TTM YoY, FY22 Q3: -100.0% Revenue growth, TTM YoY, FY22 Q4: -100.0% Revenue growth, TTM YoY, FY25 Q4: 181.5% Revenue growth, TTM YoY, FY26 Q1: -20.3% Revenue growth, TTM YoY, FY26 Q2: -62.1% -62.1%

Source: SEC EDGAR filings. Retrieved October 29, 2026.

View chart data
Period Revenue growth, TTM YoY
FY21 Q2 -21.2%
FY21 Q3 -24.3%
FY21 Q4 -62.0%
FY22 Q1 -72.6%
FY22 Q2 -100.0%
FY22 Q3 -100.0%
FY22 Q4 -100.0%
FY25 Q4 181.5%
FY26 Q1 -20.3%
FY26 Q2 -62.1%
Operating margin (TTM) Korro Bio, Inc.
-6000% -4000% -2000% 0% FY21 Q1 FY21 Q4 FY25 Q1 FY26 Q2 Operating margin (TTM), FY21 Q1: -122.5% Operating margin (TTM), FY21 Q2: -151.4% Operating margin (TTM), FY21 Q3: -303.7% Operating margin (TTM), FY21 Q4: -597.3% Operating margin (TTM), FY22 Q1: -924.8% Operating margin (TTM), FY24 Q4: -4047.1% Operating margin (TTM), FY25 Q1: -1980.4% Operating margin (TTM), FY25 Q2: -1569.1% Operating margin (TTM), FY25 Q3: -1282.0% Operating margin (TTM), FY25 Q4: -1906.4% Operating margin (TTM), FY26 Q1: -3052.3% Operating margin (TTM), FY26 Q2: -4625.5% -4625.5%

Source: SEC EDGAR filings. Retrieved October 29, 2026.

View chart data
Period Operating margin (TTM)
FY21 Q1 -122.5%
FY21 Q2 -151.4%
FY21 Q3 -303.7%
FY21 Q4 -597.3%
FY22 Q1 -924.8%
FY24 Q4 -4047.1%
FY25 Q1 -1980.4%
FY25 Q2 -1569.1%
FY25 Q3 -1282.0%
FY25 Q4 -1906.4%
FY26 Q1 -3052.3%
FY26 Q2 -4625.5%
FCF margin (TTM) Korro Bio, Inc.
-4000% -3000% -2000% -1000% 0% FY21 Q1 FY21 Q4 FY25 Q1 FY26 Q2 FCF margin (TTM), FY21 Q1: -198.3% FCF margin (TTM), FY21 Q2: -217.4% FCF margin (TTM), FY21 Q3: -334.2% FCF margin (TTM), FY21 Q4: -561.4% FCF margin (TTM), FY22 Q1: -746.6% FCF margin (TTM), FY24 Q4: -3433.6% FCF margin (TTM), FY25 Q1: -1556.6% FCF margin (TTM), FY25 Q2: -1175.9% FCF margin (TTM), FY25 Q3: -952.9% FCF margin (TTM), FY25 Q4: -1237.2% FCF margin (TTM), FY26 Q1: -1837.7% FCF margin (TTM), FY26 Q2: -2865.9% -2865.9%

Source: SEC EDGAR filings. Retrieved October 29, 2026.

View chart data
Period FCF margin (TTM)
FY21 Q1 -198.3%
FY21 Q2 -217.4%
FY21 Q3 -334.2%
FY21 Q4 -561.4%
FY22 Q1 -746.6%
FY24 Q4 -3433.6%
FY25 Q1 -1556.6%
FY25 Q2 -1175.9%
FY25 Q3 -952.9%
FY25 Q4 -1237.2%
FY26 Q1 -1837.7%
FY26 Q2 -2865.9%

Data: SEC EDGAR XBRL company facts (as filed in 10-K/10-Q); forms 10-K, 10-K/A, 10-Q. Generated November 3, 2026. Definitions in our methodology.

Financial statements

US$ millions unless shown otherwise. Fiscal years, plus the last twelve months (LTM) when newer.

Fiscal year 2019 Dec 2019 2020 Dec 2020 2021 Dec 2021 2022 Dec 2022 2023 Dec 2023 2024 Dec 2024 2025 Dec 2025 LTM Jun 2026
Income
Revenue 29 37 14 0 0 2 6 2
EBITDA −20 −26 −81 −56 −81 −88 −118 −108
Operating income −21 −28 −84 −59 −85 −92 −122 −110
Net income −19 −27 −85 −58 −81 −84 −117 −107
Diluted EPS −$114.50 −$0.82 −$123.50 −$227.42 −$53.08 −$9.37 −$12.48 −$8.88
Growth (year on year)
Revenue — +27.8% −62.0% −100.0% — — +181.5% −62.1%
Margins
EBITDA margin −68.6% −71.4% −577.6% — — <−999% <−999% <−999%
Operating margin −71.4% −74.5% −597.3% — — <−999% <−999% <−999%
Net margin −64.8% −71.7% −602.0% — — <−999% <−999% <−999%
Free-cash-flow margin 114.5% −140.2% −561.4% — — <−999% <−999% <−999%
Cash flow
Cash from operations 34 −45 −76 −54 −67 −60 −79 −68
Capital spending 1 7 3 5 8 18 1 0
Free cash flow 33 −52 −79 −59 −75 −78 −79 −68
Stock-based pay 4 10 22 20 2 4 8 9
Free cash flow after stock pay 30 −62 −101 −79 −78 −82 −87 −78
Balance sheet
Cash 200 220 80 36 166 56 22 25
Total debt 0 — 1 10 0 0 0 0
Net debt (negative = net cash) −200 −220 −79 −26 −166 −56 −22 −25
Diluted shares — — — — 2m 9m 9m 12m

Source: SEC EDGAR XBRL company facts (US and foreign periodic filings); column headings link to the filing. EBITDA is operating income plus depreciation and amortisation. Free cash flow is cash from operations minus capital spending. Growth is left blank when last year's figure was a loss or under 2% of revenue. Share counts and EPS are restated for stock splits. A dash means the company didn't report the figure.

Financial health

2 of 2 checks passed · June 30, 2026
What it owns · $163m
Short-term assets $121mLonger-term assets $43m
What it owes, and who funded it · $163m
Short-term liabilities $13mLonger-term liabilities $48mShareholders' equity $103m
  • Short-term assets cover short-term liabilities $121m of assets due within a year against $13m of liabilities due within a year.
  • Short-term assets cover long-term liabilities $121m short-term assets against $48m of longer-dated liabilities.
  • More cash than debt Cash or debt not separately reported. Not assessable.
  • Debt below 40% of shareholders' equity Equity or debt not reported. Not assessable.
  • Debt burden no higher than five years ago Five-year comparison not available. Not assessable.
  • A year's operating cash flow covers at least 20% of debt Cash flow or debt not reported. Not assessable.
  • Operating profit covers interest at least five times over Interest not separately reported. Not assessable.

From Korro Bio, Inc.'s latest balance sheet as filed. Checks are fixed, documented rules (methodology), counted only where the company reports the figures — a dot means the filing doesn't break the item out. Descriptions of reported data, not advice.

Dividends, buybacks and capital spending

Diluted share count
+28.2%
year over year
R&D spending
2155.5%
of revenue

Competitors: side by side with peers

Closest by revenue in biotechnology
Last 12 months unless stated KRRO CLGN VTGN KRSA MCRB UPB Median
Revenue, last 12 months $2m $2m $3m $2m $2m $3m $56m
Revenue growth, last 12 months −62.1% 360.4% 287.3% −12.6% 100.0% 16.0% 12.6%
Revenue growth, 3-year average −53.7% — — — −75.6% — 13.7%
Revenue growth, latest quarter −100.0% — 504.9% −100.0% 100.0% −17.5% 10.2%
Operating margin <−999% −484.3% <−999% −359.2% <−999% <−999% −189.4%
Operating margin, 3-year average <−999% — <−999% <−999% <−999% <−999% −363.5%
Net margin <−999% −484.6% <−999% −353.0% <−999% <−999% −169.8%
Cash from operations / revenue <−999% −397.3% <−999% −234.3% <−999% <−999% −168.0%
Free-cash-flow margin <−999% −398.4% <−999% <−999% <−999% <−999% −162.4%
Free-cash-flow margin, 3-year average <−999% — <−999% — −900.2% — −310.0%
Stock pay / revenue 391.7% 42.1% 162.7% 16.9% 487.8% 446.5% 20.0%
Change in share count 28.2% 6.5% 30.8% 45.4% 11.0% — 8.2%

Median of all 184 companies we cover in biotechnology. Shaded: best of the six on that line (lowest for stock pay and share-count growth). 3-year figures average the last three 12-month periods; 3-year growth is compound annual. Source: SEC filings.

Peer comparison

184 biotechnology companies
Measure Company Peer median Rank
Revenue growth Growth -62.1% 12.6% 148 of 172
Change in growth rate Growth -41.8pp -0.1pp 141 of 172
Operating margin Profitability -4625.5% -189.4% 158 of 175
Net margin Profitability -4477.1% -157.3% 163 of 180
Free-cash-flow margin Cash generation -2865.9% -145.4% 157 of 176
Stock pay as % of revenue Cash generation 391.7% 19.2% 160 of 179
Change in share count Balance sheet 28.2% 7.9% 127 of 156

Rank 1 = best in the group (for spending, debt and dilution, lower ranks first).

Who owns it

Funds buying and selling
Reported value
$199M
Institutions reporting
107
Shares held vs prior quarter
▲ 17.8%
Positions opened / closed
19 / 11

Top buyers and sellers, Q2 2026: 67 institutions bought and 30 sold ; the biggest buyer was Nantahala Capital Management, LLC (+660K shares) and the biggest seller Atlas Venture Life Science Advisors, LLC (−174K). See which funds bought and sold →

Largest reported holders, June 30, 2026
Manager Value Shares Share of 13F value Shares QoQ
Lynx1 Capital Management LP $20.3M 1.5M 10.2% 0.0%
Nantahala Capital Management, LLC $17.4M 1.3M 8.8% ▲ 100.0%
Nea Management Company, LLC $17.1M 1.3M 8.6% 0.0%
Venrock Adviser, LLC $13.3M 1.0M 6.7% 0.0%
Atlas Venture Life Science Advisors, LLC $12.7M 963K 6.4% ▼ 15.3%
Balyasny Asset Management L.P. $12.5M 952K 6.3% ▼ 8.5%
Blackrock, Inc. $10.8M 818K 5.4% ▲ 77.7%
Affinity Asset Advisors, LLC $9.3M 707K 4.7% 0.0%
Adage Capital Partners Gp, L.L.C. $7.1M 541K 3.6% ▲ 136.9%
ADAR1 Capital Management, LLC $7.1M 540K 3.6% 0.0%
Vanguard Capital Management LLC $6M 455K 3.0% ▲ 46.3%
Driehaus Capital Management LLC $5.9M 450K 3.0% 0.0%

From Form 13F filings with the SEC ( quarterly data sets), as reported by each manager for June 30, 2026 and filed up to 45 days later. 13F reports cover long US-listed positions of managers above $100M only, so this is not Korro Bio, Inc.'s complete shareholder register. Values are as reported by the filers .

Insider trading activity

Full insider history and chart
Insider purchases History → $21.7M 16 trades by 11 insiders, last 12 months Insider sales History → $5.7M 33 trades by 6 insiders · 92% under pre-set plans
Net ▲ $16M net buying
Insider Date Trade Shares Price Value
Lynx1 Capital Management Lp 10% owner October 26, 2026 Buy 25,124 $11.75 $295,091
Lynx1 Capital Management Lp 10% owner October 23, 2026 Buy 2,510 $12.11 $30,386
Lynx1 Capital Management Lp 10% owner October 22, 2026 Buy 40,000 $11.04 $441,464
Lynx1 Capital Management Lp 10% owner October 22, 2026 Buy 12,175 $9.68 $117,810
Formela Jean Francois Director September 14, 2026 Sell pre-set plan 6,602 $14.12 $93,220
Formela Jean Francois Director September 14, 2026 Sell pre-set plan 31,888 $14.12 $450,259
Dolan Oliver Senior Vice President, Finance September 11, 2026 Sell pre-set plan 5 $13.72 $69
Formela Jean Francois Director September 11, 2026 Sell pre-set plan 8,450 $13.99 $118,216
Formela Jean Francois Director September 11, 2026 Sell pre-set plan 1,750 $13.99 $24,482
Dolan Oliver Senior Vice President, Finance September 9, 2026 Sell pre-set plan 6 $13.60 $82
Dolan Oliver Senior Vice President, Finance September 8, 2026 Sell pre-set plan 7,347 $13.51 $99,258
Formela Jean Francois Director August 26, 2026 Sell pre-set plan 51 $13.96 $712

From insiders' Form 4 filings with the SEC. Excludes awards, option exercises and shares withheld for tax. "Pre-set plan" means the filing marks the trade as made under a Rule 10b5-1 plan. See every insider trade since five years ago, on a price chart.

Earnings dates and SEC filings

Results announcements

Next expected around November 6, 2026 estimated from the company's past filing pattern, not announced

  • August 6, 2026
  • May 7, 2026
  • March 12, 2026
  • March 9, 2026
  • November 12, 2025
  • August 12, 2025

Recent SEC filings

Data status

When each part of this page on Korro Bio, Inc. was last updated.

DataLast updatedSource
Share priceExchange closing prices
Financial statementsSEC 10-K and 10-Q filings
News and updatesCompany releases and SEC 8-K filings
Analyst estimatesAggregated analyst estimates
Valuation and scoresOur models, from the filed figures

How we build and check these figures: methodology and data sources.

Korro Bio, Inc. in brief

What does Korro Bio, Inc. do?
Korro Bio, Inc. is a US-listed company in the biotechnology industry. Its financial year ends in December.
What is Korro Bio, Inc.'s stock ticker?
Korro Bio, Inc. trades under the ticker KRRO on Nasdaq. This page brings together its financial statements, valuation models, ownership and recent company updates.
What is Korro Bio, Inc.'s revenue, and how fast is it growing?
Over its most recent trailing twelve months, Korro Bio, Inc. reported revenue of $2.4M, 62.1% lower than a year earlier, according to its SEC filings.
What is Korro Bio, Inc.'s free cash flow?
Korro Bio, Inc.'s free-cash-flow margin is -2865.9% of revenue over the trailing twelve months, ranking 157 of the 176 biotechnology companies we cover.
Who are Korro Bio, Inc.'s largest institutional shareholders?
By value reported in 13F filings for June 30, 2026, the largest reported holders are Lynx1 Capital Management LP, Nantahala Capital Management, LLC and Nea Management Company, LLC. 13F reports cover long US-listed positions of managers above $100M, filed up to 45 days after quarter end.
What is Korro Bio, Inc.'s market cap?
On November 2, 2026, Korro Bio, Inc.'s market capitalisation was about $190M and net debt of -$24.9M. Market figures come from third-party market data and may be delayed.
Who are Korro Bio, Inc.'s competitors?
In our Biotechnology peer group, the companies closest to Korro Bio, Inc. are Collplant Biotechnologies Ltd, Vistagen Therapeutics, Inc., Korsana Biosciences, Inc., Seres Therapeutics, Inc. and Upstream Bio, Inc. The side-by-side comparison below sets their revenue, margins and growth against Korro Bio, Inc.'s.
Are insiders buying or selling Korro Bio, Inc. stock?
Over the last 12 months, Korro Bio, Inc.'s directors and officers reported 16 open-market purchases and 33 sales on Form 4. The insider trading page charts every trade.
When is Korro Bio, Inc.'s next earnings date?
Around November 12, 2026, estimated from the spacing of its past results announcements (8-K filings). That is an estimate, not a confirmed date — Korro Bio, Inc. announces its own schedule.