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KRRO · Korro Bio, Inc.
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KRRO Korro Bio (KRRO) Insider Trading, Ownership & Congress Trades

Pharma & Biotech · Pharmaceutical preparations · CIK 0001703647
Quote by TradingView
Form 144 · 14
House members buying, 1 year
0
STOCK Act, US House only, disclosed up to 45 days after the trade
Funds added, last quarter
67
13F, latest reported quarter

What the filings say about KRRO

Insiders, 180 days
-$4.7M net sold
1 buyer · 6 sellers · 33% of sales under a 10b5-1 plan
Planned sales (Form 144), 90 days
$1.8M
14 notices

Korro Bio insider trades (Form 4)

Form 4 buys and sells (codes P and S). Grants, option exercises and conversions excluded.

Over the last 180 days, Korro Bio, Inc. insiders sold a net $4.7M of stock across 82 Form 4 purchases and sales, with 1 insider buying. Source: SEC Form 4 filings, as of 2026-10-28.

Insider
Filed
Shares
Value
Since filing
Lynx1 Capital Management LP
BUY
2026-10-26 SEC
25,124
$295.1K
n/a
Context
  • 5 earlier Form 4 trades (code P or S) here by this insider (5 buys), the last on Oct 23, 2026.
  • The trade is 1.5% of the 1,624,789 shares held after it.
  • No other insider bought within 30 days.
  • 67 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Insider Lynx1 Capital Management LP bought about $295.1K of KRRO on Oct 26, 2026; 67 funds added in the latest 13F quarter.
Lynx1 Capital Management LP
BUY
2026-10-26 SECtraded 2026-10-23
2,510
$30.4K
n/a
Context
  • 4 earlier Form 4 trades (code P or S) here by this insider (4 buys), the last on Oct 22, 2026.
  • The trade is 0.2% of the 1,599,665 shares held after it.
  • No other insider bought within 30 days.
  • 67 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Insider Lynx1 Capital Management LP bought about $30.4K of KRRO on Oct 23, 2026; 67 funds added in the latest 13F quarter.
Lynx1 Capital Management LP
BUY
2026-10-26 SECtraded 2026-10-22
12,175
$117.8K
n/a
Context
  • 2 earlier Form 4 trades (code P or S) here by this insider (2 buys), the last on Aug 10, 2026.
  • The trade is 0.8% of the 1,557,155 shares held after it.
  • No other insider bought within 30 days.
  • 67 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Insider Lynx1 Capital Management LP bought about $117.8K of KRRO on Oct 22, 2026; 67 funds added in the latest 13F quarter.
Lynx1 Capital Management LP
BUY
2026-10-26 SECtraded 2026-10-22
40,000
$441.5K
n/a
Context
  • 2 earlier Form 4 trades (code P or S) here by this insider (2 buys), the last on Aug 10, 2026.
  • The trade is 2.5% of the 1,597,155 shares held after it.
  • No other insider bought within 30 days.
  • 67 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Insider Lynx1 Capital Management LP bought about $441.5K of KRRO on Oct 22, 2026; 67 funds added in the latest 13F quarter.
FORMELA JEAN FRANCOIS
Director
SELL
2026-09-15 SECtraded 2026-09-14
31,888
$450.3K
-13.1%
Context
  • 22 earlier Form 4 trades (code P or S) here by this insider (22 sales), the last on Sep 11, 2026.
  • The trade is 5.0% of the 640,610 shares held after it.
  • 1 other insider sold within 30 days.
  • 67 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Director FORMELA JEAN FRANCOIS sold about $450.3K of KRRO under a 10b5-1 plan on Sep 14, 2026; 1 other insider sold within 30 days and 67 funds added in the latest 13F quarter.
82 transactions on record
Since filing: total return from the first close after the filing to the latest close, dividend-adjusted. Not a forecast.
Context lines are counts over the filings above and returns from our own price history, never a price level. Not investment advice.
See all insider buying · insider selling
Showing the latest few. to see 77 more transactions and use the screener and CSV export. We store only your email; there is no password.
Seven facts, ranked against the sector · Rank is not a forecast
Insiders
net -$4.7M over 180 days
-$317.6K over 90 days · +$963.6K of it by a 10%+ holder
below 79% of Pharma & Biotech
Congress
no House purchase disclosed in the last 12 months
Funds
67 funds bought in last quarter
more than 55% of Pharma & Biotech
Revenue
+181.5% year over year
more than 89% of Pharma & Biotech
Margin
-1834.5% net margin
below 91% of Pharma & Biotech
Buybacks
no share repurchases reported
Short interest
16.4% of the float short (float per yahoo 2026-10-27) · 9.6 days to cover · settled 2026-10-15
more than 78% of Pharma & Biotech
What changed in the last 30 days
Oct 26Insider Lynx1 Capital Management LP bought $884.8K (4 trades, Oct 22 to Oct 26)

Watch KRRO

A free account keeps a watchlist and can send one email a day when insiders, funds or Congress file on the names in it. No password and no card.

The year, with the filings on it
Total return over 12 months. Each marker is a filing; hover or tap one for the detail.
-67.9%12M
-86%-54%-23%+9%2025-102025-122026-022026-042026-062026-082026-10 2026-03-10 · Yang Rick bought $2.3M2026-03-10 · SANDELL SCOTT D bought $2.3M2026-03-10 · New Enterprise Associates 17, L.P. bought $2.3M2026-03-10 · Chang Carmen bought $2.3M2026-03-10 · BASKETT FOREST bought $2.3M2026-03-10 · Mathers Edward T bought $2.3M2026-03-10 · Makhzoumi Mohamad bought $2.3M2026-03-10 · Walker Paul Edward bought $2.3M2026-03-10 · Florence Anthony A. Jr. bought $2.3M2026-06-23 · FORMELA JEAN FRANCOIS sold $1.4M2026-07-02 · FORMELA JEAN FRANCOIS sold $1.2M2026-06-24 · FORMELA JEAN FRANCOIS sold $593.9K2026-09-14 · FORMELA JEAN FRANCOIS sold $450.3K2026-10-22 · Lynx1 Capital Management LP bought $441.5K2026-08-19 · FORMELA JEAN FRANCOIS sold $330.2K2026-10-26 · Lynx1 Capital Management LP bought $295.1K2026-06-23 · FORMELA JEAN FRANCOIS sold $248.3K2026-07-02 · FORMELA JEAN FRANCOIS sold $206.9K2026-05-29 · Aiyar Ram sold $196.7K2026-07-06 · FORMELA JEAN FRANCOIS sold $118.7K2026-09-11 · FORMELA JEAN FRANCOIS sold $118.2K2026-10-22 · Lynx1 Capital Management LP bought $117.8K2026-06-24 · FORMELA JEAN FRANCOIS sold $101.9K2026-09-08 · Dolan Oliver sold $99.3K2026-09-14 · FORMELA JEAN FRANCOIS sold $93.2K2026-06-16 · Cerio Jeffrey sold $71.6K2026-08-19 · FORMELA JEAN FRANCOIS sold $68.4K2026-08-04 · Aiyar Ram sold $62.9K2026-08-06 · Lynx1 Capital Management LP bought $59.5K2026-06-22 · FORMELA JEAN FRANCOIS sold $47.2K2026-06-16 · Vincent Loic A sold $37.0K2026-06-16 · Dolan Oliver sold $36.6K2026-06-16 · Chappell Todd sold $34.3K2026-05-28 · FORMELA JEAN FRANCOIS sold $34.1K2026-10-23 · Lynx1 Capital Management LP bought $30.4K2026-08-11 · FORMELA JEAN FRANCOIS sold $24.8K2026-09-11 · FORMELA JEAN FRANCOIS sold $24.5K2026-08-10 · Lynx1 Capital Management LP bought $19.3K2026-07-06 · FORMELA JEAN FRANCOIS sold $11.4K2026-06-24 · FORMELA JEAN FRANCOIS sold $10.0K2026-06-22 · FORMELA JEAN FRANCOIS sold $8.1K2026-05-28 · FORMELA JEAN FRANCOIS sold $5.8K2026-09-14 · Atlas Venture Fund XI, L.P. filed to sell $440.4K2026-09-14 · Atlas Venture Opportunity Fund II, L.P. filed to sell $91.2K2026-09-11 · Atlas Venture Fund XI, L.P. filed to sell $110.4K2026-09-11 · Atlas Venture Opportunity Fund II, L.P. filed to sell $22.9K2026-09-11 · Dolan Oliver filed to sell $692026-09-09 · Dolan Oliver filed to sell $822026-09-08 · Dolan Oliver filed to sell $99.3K2026-08-26 · Atlas Venture Fund XI, L.P. filed to sell $3.4K2026-08-26 · Atlas Venture Opportunity Fund II, L.P. filed to sell $7002026-08-19 · Atlas Venture Fund XI, L.P. filed to sell $311.8K2026-08-19 · Atlas Venture Opportunity Fund II, L.P. filed to sell $64.6K2026-08-11 · Atlas Venture Fund XI, L.P. filed to sell $23.9K2026-08-11 · Atlas Venture Opportunity Fund II, L.P. filed to sell $5.0K2026-08-04 · Aiyar Ram filed to sell $662.9K2026-07-06 · Atlas Venture Fund XI, L.P. filed to sell $11.4K2026-07-06 · Atlas Venture Opportunity Fund II, L.P. filed to sell $119.1K2026-07-02 · Atlas Venture Fund XI, L.P. filed to sell $1.2M2026-07-02 · Atlas Venture Opportunity Fund II, L.P. filed to sell $201.3K2026-06-24 · Atlas Venture Fund XI, L.P. filed to sell $566.8K2026-06-24 · Atlas Venture Opportunity Fund II, L.P. filed to sell $97.2K
Insider buyInsider sellForm 144 (planned sale)
Indexed to 100, dividend-adjusted, not a price chart. When a name files heavily, the largest trades are drawn first.

Who owns KRRO: institutional holders (13F)

13F holdings, latest reported quarter
Lynx1 Capital Management LP
3,076,592 sh
$40.5M
Nantahala Capital Management, LLC
1,320,072 sh
$17.4M
NEA Management Company, LLC
1,297,893 sh
$17.1M
Venrock Adviser, LLC
1,009,500 sh
$13.3M
Atlas Venture Life Science Advisors, LLC
962,884 sh
$12.7M

Congress trades in KRRO

No Congress trades reported
No House member has disclosed a trade in this stock. See what Congress is buying.

Activist and 5% holders (13D/13G)

No 5%+ ownership filings
Nobody has filed for crossing 5%. That is a fact, not missing data.

KRRO planned insider sales (Form 144)

Notice of intent to sell, filed before any sale
Atlas Venture Fund XI, L.P.
Filed 2026-09-14
$440.4K
Atlas Venture Opportunity Fund II, L.P.
Filed 2026-09-14
$91.2K
Atlas Venture Fund XI, L.P.
Filed 2026-09-11
$110.4K
Atlas Venture Opportunity Fund II, L.P.
Filed 2026-09-11
$22.9K
Dolan Oliver
Filed 2026-09-11
$69

KRRO mutual fund holders (N-PORT)

Funds ranked by the share of their own portfolio in this stock (N-PORT).
F/m Emerald Life Sciences Innovation ETF
$842.9K position · as of 2026-05-31
0.8%
VANGUARD STRATEGIC SMALL-CAP EQUITY FUND
$1.4M position · as of 2026-06-30
0.0%
iShares Micro-Cap ETF
$448.7K position · as of 2026-06-30
0.0%
1290 VT Micro Cap Portfolio
$29.9K position · as of 2026-06-30
0.0%
SMALL COMPANY GROWTH PORTFOLIO
$192.7K position · as of 2026-06-30
0.0%
BlackRock Advantage SMID Cap V.I. Fund
$19.4K position · as of 2026-06-30
0.0%
SEC N-PORT, monthly, about 60 days late · funds ≥ $10M · % is the share of the fund's own portfolio
Clinical pipeline
2 registered trials, 1 still running (ClinicalTrials.gov). A status change is dated here weeks before the press release.
2
Multi-phase
1 active
What changed recently
Phase 1/2 Study of KRRO-121 in Healthy Volunteers and Patients With UCD
2026-10-09 · Not Yet Recruiting → Recruiting
PHASE1,PHASE2
Matched by sponsor name. Trials run under a subsidiary's own name are not included.
Live price
Daily candles from TradingView, under their licence. No filings marked.
Why this name is on the desk
Insiders have filed to sell, before selling.
The record shows a net $4.7M sold by insiders over 180 days, 67 funds added last quarter, $1.8M in planned Form 144 sales. Each figure is a federal filing, dated the day it went public.
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Sector by SEC SIC code
UTHRCPIXMRNAREGNLLYALNYMDGLCITRDNAVRTXNUVLTWST

KRRO financials

Revenue growth
+181.5%
XBRL, annual
Net margin
-1834.5%
Ratios from the company's XBRL filings, latest filings
Revenue, TTM
$2.4M
four quarters, 2025-07-01 to 2026-06-30
Net margin, TTM
-4,477%
net income over revenue, 2025-07-01 to 2026-06-30
Free cash flow, TTM
-$68.3M
operating cash flow minus capex, 2025-07-01 to 2026-06-30
Debt to equity
0.00x
long-term 2019-12-31 (79 months older than the period end) plus current 2023-09-30 (33 months older than the period end); equity 2026-06-30
Cash flow to debt
-377.49x
TTM operating cash flow over long-term 2019-12-31 (79 months older than the period end) plus current 2023-09-30 (33 months older than the period end)
Return on equity
-97.7%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on assets
-62.0%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on invested capital
n/a
pre-tax loss, no effective tax rate to apply
Return on capital employed
-70.2%
operating income (EBIT proxy) over average of 2025-06-30 and 2026-06-30 minus current liabilities
P/E, trailing
n/a
trailing loss, a multiple of a loss is not meaningful
Enterprise value
$152.3M
market value at close 2026-10-26 on 2026-08-05 shares, plus long-term 2019-12-31 (79 months older than the period end) plus current 2023-09-30 (33 months older than the period end), minus cash 2026-06-30
FCF yield
-38.6%
TTM free cash flow over market value at close 2026-10-26
PEG, trailing
n/a
trailing loss, a multiple of a loss is not meaningful
Price as of 2026-10-26. Hover or tap a tile for its yearly and quarterly history.
Method
TTM is four consecutive fiscal quarters; Q4 is the year minus nine months when not filed. Returns use the average of opening and closing balances. EBIT is approximated by operating income. PEG uses trailing EPS growth.
Fundamentals
Annual figures from XBRL filings. Pick a past date to see them as known then.
2025-122024-122023-122023-11
Revenue$6.4M$2.3M$0n/a
Operating income-$121.9M-$91.9M-$84.5Mn/a
Net income-$117.3M-$83.6M-$81.2Mn/a
EPS (diluted)-12.48-9.37-53.08n/a
Operating cash flow-$78.6M-$60.1M-$67.3Mn/a
Cash$21.8M$55.6M$166.2M$36.6M
SEC XBRL, fiscal years, as known on 2026-10-28

KRRO Stock Sonar score 6/7 axes

Find similar shapesCompare

KRRO ranks highest on growth (89th percentile) and institutional and government (55th), and lowest on risk and compliance (32nd), among Pharma & Biotech peers.

ProfitHealthGrowthInsidersInstitutionsRisk
Profitability
36
Inputs
  • Return on equity-97.7% · 34 pct, sector of 545
  • Return on assets-62.0% · 38 pct, sector of 691
  • Return on invested capitalpre-tax loss, no effective tax rate to apply
  • Return on capital employed-70.2% · 36 pct, sector of 576
Financial health
44
Inputs
  • Debt to equity0.00x · 84 pct, sector of 352
  • Cash flow to debt-377.49x · 4 pct, sector of 371
Growth
89
Inputs
  • Revenue growth, YoY+181.5% · 89 pct, sector of 505
  • Backlog growth, YoYno backlog line filed, or no year-earlier backlog
Insider conviction
39
Inputs
  • Net Form 4 buying (codes P and S), 180d-$3.5M · 22 pct, sector of 428
  • Insider buyers, 180d1 · 56 pct, sector of 437
Institutional and government
55
Inputs
  • Funds adding, latest quarter67 · 55 pct, sector of 698
  • Congress net buyers, 365dno Congress trades in 365 days
  • Federal contracts, 180dno federal contracts in 180 days
  • Lobbying spend, 4 quartersno lobbying filings in the last four quarters
Risk and compliance
32
Inputs
  • Short interest, % of float+15.8% · 24 pct, sector of 813
  • Recalls per $1B revenue, 3yrevenue under $50M or not filed, so a count cannot be scaled to size
  • EPA cases per $1B revenue, 5yrevenue under $50M or not filed, so a count cannot be scaled to size
  • New text in Risk Factors, latest 10-K+12.8% · 40 pct, sector of 511
1 not measured: US patents
  • US patents needs 1 of 2 inputs, 0 present: patent data not loaded yet

6 of 7 axes scored. Each is a percentile against sector peers (all companies when the sector is thin); higher is better. An unscored axis is unmeasured, not low. How it is scored

KRRO filings, in plain words

Are Korro Bio insiders buying or selling KRRO?

In the 180 days to 2026-10-28, Korro Bio insiders were net sellers, a net $4.7M: $963.6K of purchases and $5.7M of sales reported on Form 4, by 1 buyer and 6 sellers.

Are there planned insider sales of KRRO?

Yes. 14 Form 144 notices of planned insider sales were filed in the 90 days to 2026-10-28, covering $1.8M of stock; the latest, by Atlas Venture Fund XI, L.P., was filed 2026-09-14.

Read the full summary

In the 180 days to 2026-10-28, Korro Bio insiders were net sellers of KRRO, a net $4.7M across purchases and sales reported on Form 4 by 1 buyer and 6 sellers. 33% of the 33 insider sales were made under a Rule 10b5-1 plan; the rest were not flagged as planned. Insiders filed 14 Form 144 notices of intent to sell in the 90 days to 2026-10-28, covering $1.8M of stock. Each figure is counted from SEC and House filings as of 2026-10-28, dated the day the filing was made public.

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