Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

Korro Bio, Inc.

KRRO · Nasdaq · CIK 0001703647 · Healthcare · Biotechnology

INSIDER SIGNAL

No active buy signal

2 qualifying P purchase groups
in the current 180-day scoring window

40 Form 4 transaction lines observed in the same window
33 sales · 5 option, withholding, award, gift or other lines

Last qualifying purchase2026-08-10 · Lynx1 Capital Management LP; Nichols Weston · $19.3K

WHY NO ACTIVE SIGNAL?

Purchase activityPresent
Recent buying2 qualifying line group(s)
Recent salesHigh
Buy signal statusInactive
Score anatomy

No score is calculated because there is no qualifying purchase in the active window. Unavailable inputs are not treated as zero or as a bearish signal.

ClusterNot calculated
Purchase sizeNot calculated
RoleNot calculated
RecencyNot calculated
ConvictionNot calculated

Why is there no score?

  • No qualifying open-market purchase supplies cluster, size, role, recency or conviction inputs.
  • Sales and other Form 4 activity remain visible as context and do not create a negative score.

Sales and other Form 4 activity are shown separately and do not create a negative buy signal. Absence of buying is not scored as bearish.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
FORMELA JEAN FRANCOISDirector
▼▼▼▼▼▼▼▼▼▼▼
Dolan OliverSenior Vice President, Finance
▼○▼▼▼
Aiyar RamPresident and CEO
○▼▼
Lynx1 Capital Management LP; Nichols WestonTenPercentOwner
●●
Vincent Loic AChief Scientific Officer
▼○
Cerio JeffreyGeneral Counsel
▼○
● Purchase▼ Sale○ Other

Showing the six most active owners; 1 additional owner(s) remain in Form 4 evidence.

Purchase breadth & concentration

QUALIFYING BUYERS1
PURCHASE CONCENTRATION100%Largest buyer: Lynx1 Capital Management LP; Nichols Weston · $78.8K
CLUSTER BUYING · 15D1 insiderPeak activity: 2026-08-06–2026-08-10

Roles in the peak window: TenPercentOwner. Concentration uses priced qualifying P lines only and does not change the saved score.

SIGNAL HISTORY

No recorded active-signal snapshot

Scores are archived only when the company qualifies for a published US buy-signal snapshot. Last qualifying purchase: 2026-08-10 · Lynx1 Capital Management LP; Nichols Weston.

Recent Form 4 activity

11Purchases
33Sales
11Other Form 4 lines
36SEC filings · 365 days
BUYING2 qualifying P line(s) · 180 days
SELLING33 sale line(s) · context only
OTHER5 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context has not been captured for this ticker yet. The daily market-context job processes the US universe in rotating batches.

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
1,675,219
Previous report
1,551,984
Avg daily volume
255,628
Days to cover
6.5

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2026-08-10Lynx1 Capital Management LP; Nichols WestonPurchase (P)Common stock, $0.001 par value per share1,462USD 13.19USD 19,284SEC filing ↗
2026-08-06Lynx1 Capital Management LP; Nichols WestonPurchase (P)Common stock, $0.001 par value per share5,222USD 11.40USD 59,531SEC filing ↗
2026-03-10Yang RickPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10Walker Paul EdwardPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10SANDELL SCOTT DPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10NEA 17 GP, LLC; NEA Partners 17, L.P.; New Enterprise Associates 17, L.P.Purchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10Mathers Edward TPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10Makhzoumi MohamadPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10Florence Anthony A. Jr.Purchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10Chang CarmenPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10BASKETT FORESTPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2024-04-22Yang RickPurchase (P)Common Stock17,857USD 56.00USD 999,992SEC filing ↗
2024-04-22Walker Paul EdwardPurchase (P)Common Stock17,857USD 56.00USD 999,992SEC filing ↗
2024-04-22SANDELL SCOTT DPurchase (P)Common Stock17,857USD 56.00USD 999,992SEC filing ↗
2024-04-22NEA 17 GP, LLC; NEA Partners 17, L.P.; New Enterprise Associates 17, L.P.Purchase (P)Common Stock17,857USD 56.00USD 999,992SEC filing ↗

Form 4 evidence

55 transaction lines in the latest 365-day window; 392 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-14FORMELA JEAN FRANCOISSale (S)Common Stock38,490USD 14.12USD 543,479SEC filing ↗
2026-09-11FORMELA JEAN FRANCOISSale (S)Common Stock10,200USD 13.99USD 142,698SEC filing ↗
2026-09-11Dolan OliverSale (S)Common Stock5USD 13.72USD 69SEC filing ↗
Show recent Form 4 evidence (30 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-14FORMELA JEAN FRANCOISSale (S)Common Stock38,490USD 14.12USD 543,479SEC filing ↗
2026-09-11FORMELA JEAN FRANCOISSale (S)Common Stock10,200USD 13.99USD 142,698SEC filing ↗
2026-09-11Dolan OliverSale (S)Common Stock5USD 13.72USD 69SEC filing ↗
2026-09-09Dolan OliverSale (S)Common Stock6USD 13.60USD 82SEC filing ↗
2026-09-08Dolan OliverSale (S)Common Stock7,347USD 13.51USD 99,258SEC filing ↗
2026-08-26FORMELA JEAN FRANCOISSale (S)Common Stock300USD 13.96USD 4,188SEC filing ↗
2026-08-19FORMELA JEAN FRANCOISSale (S)Common Stock28,468USD 14.00USD 398,552SEC filing ↗
2026-08-11FORMELA JEAN FRANCOISSale (S)Common Stock2,143USD 13.96USD 29,916SEC filing ↗
2026-08-10Lynx1 Capital Management LP; Nichols WestonPurchase (P)Common stock, $0.001 par value per share1,462USD 13.19USD 19,284SEC filing ↗
2026-08-06Lynx1 Capital Management LP; Nichols WestonPurchase (P)Common stock, $0.001 par value per share5,222USD 11.40USD 59,531SEC filing ↗
2026-08-04Aiyar RamSale (S)Common Stock5,802USD 10.84USD 62,894SEC filing ↗
2026-07-15Vincent Loic AAward / grant (A)Common Stock7,500USD 0.00USD 0SEC filing ↗
2026-07-15Dolan OliverAward / grant (A)Common Stock5,500USD 0.00USD 0SEC filing ↗
2026-07-15Chappell ToddAward / grant (A)Common Stock7,500USD 0.00USD 0SEC filing ↗
2026-07-15Cerio JeffreyAward / grant (A)Common Stock6,500USD 0.00USD 0SEC filing ↗
2026-07-06FORMELA JEAN FRANCOISSale (S)Common Stock9,323USD 13.96USD 130,149SEC filing ↗
2026-07-02FORMELA JEAN FRANCOISSale (S)Common Stock100,700USD 14.03USD 1,412,821SEC filing ↗
2026-06-24FORMELA JEAN FRANCOISSale (S)Common Stock48,438USD 14.61USD 707,491SEC filing ↗
2026-06-23FORMELA JEAN FRANCOISSale (S)Common Stock119,005USD 14.25USD 1,695,821SEC filing ↗
2026-06-22FORMELA JEAN FRANCOISSale (S)Common Stock3,962USD 13.95USD 55,270SEC filing ↗
2026-06-16Vincent Loic ASale (S)Common Stock3,418USD 10.83USD 37,017SEC filing ↗
2026-06-16Dolan OliverSale (S)Common Stock3,383USD 10.83USD 36,638SEC filing ↗
2026-06-16Chappell ToddSale (S)Common Stock3,168USD 10.83USD 34,309SEC filing ↗
2026-06-16Cerio JeffreySale (S)Common Stock6,609USD 10.83USD 71,575SEC filing ↗
2026-05-29Aiyar RamSale (S)Common Stock15,152USD 12.98USD 196,673SEC filing ↗
2026-05-28FORMELA JEAN FRANCOISSale (S)Common Stock2,860USD 13.95USD 39,897SEC filing ↗
2026-05-26Aiyar RamAward / grant (A)Common Stock50,000USD 12.33USD 616,500SEC filing ↗
2026-03-10Yang RickPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10Walker Paul EdwardPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗
2026-03-10SANDELL SCOTT DPurchase (P)Common Stock207,100USD 11.11USD 2,300,881SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerKRRO
CIK0001703647
SectorHealthcare
IndustryBiotechnology Yahoo Finance
SEC SIC2834 Pharmaceutical Preparations
ExchangeNasdaq

Data coverage

Local Form 4 history392 transaction lines from 2020-01-30 to 2026-09-14
23 P purchase lines · 283 S sale lines · 86 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.