Eric Mosbrooker

CIK: 0001715283

Transaction Breakdown

Open Market Buys (P)0 (0.0%)

High conviction signal

Open Market Sales (S)4 (33.3%)

Position reduction

Option Exercises (M)3 (25.0%)

Derivative conversions

Awards (A)2 (16.7%)

Compensation grants

Other (G, F, J, C, D, …)3 (25.0%)

Gifts, tax withholding, conversions, dispositions to the issuer and other codes

Companies & Roles (1)

RNAM

Avidity Biosciences, Inc.

Officer

Discretionary Trading P&L

Holdings

Transaction History (12 total)

RNAM
Avidity Biosciences, Inc.
Feb 27, 2026
Disposition(D)
Direct
79.4K shares-
RNA
Avidity Biosciences, Inc.
Dec 17, 2025
Tax Payment(F)
Direct
11.4K shares at avg. $71.87$821K
RNA
Avidity Biosciences, Inc.
Dec 17, 2025
Award(A)
Direct
72K shares-
RNA
Avidity Biosciences, Inc.
Dec 17, 2025
Tax Payment(F)
Direct
36.6K shares at avg. $71.87$2.6M
RNA
Avidity Biosciences, Inc.
Oct 3, 2025
Exercise(M)
Direct
6.6K shares at avg. $9.05$59K
RNA
Avidity Biosciences, Inc.
Oct 3, 2025
Sale(S)
Direct
6.6K shares at avg. $45.38$298K
RNA
Avidity Biosciences, Inc.
Sep 3, 2025
Exercise(M)
Direct
6.6K shares at avg. $9.05$59K
RNA
Avidity Biosciences, Inc.
Sep 3, 2025
Sale(S)
Direct
6.6K shares at avg. $47.07$309K
RNA
Avidity Biosciences, Inc.
Aug 6, 2025
Exercise(M)
Direct
124.7K shares at avg. $9.05$1.1M
RNA
Avidity Biosciences, Inc.
Aug 6, 2025
Sale(S)
Direct
124.7K shares at avg. $44.06$5.5M
RNA
Avidity Biosciences, Inc.
Aug 6, 2025
Sale(S)
Direct
6.1K shares at avg. $44.06$270K
RNA
Avidity Biosciences, Inc.
Jan 6, 2025
Award(A)
Direct
25K shares-

		Type	Shares	Price		Ownership
Feb 27, 2026	RNAM Avidity Biosciences, Inc.	Disposition(D)	79,413	-	$0	Direct
Dec 17, 2025	RNA Avidity Biosciences, Inc.	Tax Payment(F)	11,426	$71.87	$821,187	Direct
Dec 17, 2025	RNA Avidity Biosciences, Inc.	Award(A)	72,000	-	-	Direct
Dec 17, 2025	RNA Avidity Biosciences, Inc.	Tax Payment(F)	36,564	$71.87	$2,627,855	Direct
Oct 3, 2025	RNA Avidity Biosciences, Inc.	Exercise(M)	6,562	$9.05	$59,386	Direct
Oct 3, 2025	RNA Avidity Biosciences, Inc.	Sale(S)	6,562	$45.38	$297,771	Direct
Sep 3, 2025	RNA Avidity Biosciences, Inc.	Exercise(M)	6,563	$9.05	$59,395	Direct
Sep 3, 2025	RNA Avidity Biosciences, Inc.	Sale(S)	6,563	$47.07	$308,936	Direct
Aug 6, 2025	RNA Avidity Biosciences, Inc.	Exercise(M)	124,687	$9.05	$1,128,417	Direct
Aug 6, 2025	RNA Avidity Biosciences, Inc.	Sale(S)	124,687	$44.06	$5,494,033	Direct
Aug 6, 2025	RNA Avidity Biosciences, Inc.	Sale(S)	6,120	$44.06	$269,663	Direct
Jan 6, 2025	RNA Avidity Biosciences, Inc.	Award(A)	25,000	-	$0	Direct

1-12 of 12 transactions

About Mosbrooker Eric

Mosbrooker Eric (SEC CIK 0001715283) files insider reports with the SEC as Chief Commercial Officer of Avidity Biosciences, Inc. (RNAM).

Signal8 holds 7 ownership filings by Mosbrooker Eric (1 Form 3, 6 Form 4), filed between Jan 8, 2025 and Feb 27, 2026. Those filings report 12 transactions, from Jan 6, 2025 to Feb 27, 2026. Signal8's Form 4 history starts in Sep 2024.

The business address on Mosbrooker Eric's filings is in SAN DIEGO, CA.

Recent filings by Mosbrooker Eric

Feb 27, 2026: Disposition to issuer transaction of RNAM shares (Form 4, code D).
Dec 17, 2025: Tax withholding of RNA shares (Form 4, code F).
Dec 17, 2025: Grant or award of RNA shares (Form 4, code A).
Dec 17, 2025: Tax withholding of RNA shares (Form 4, code F).
Oct 3, 2025: Option exercise of RNA shares (Form 4, code M).

Other insiders filing for Avidity Biosciences, Inc. (RNAM)

McCarthy Teresa, Chief Human Resources Officer
Thompson Tamar, Director
MacLean Michael F, Chief Financial Officer
Skerjanec Simona, Director
Hughes Steven George, Chief Medical Officer
Boyce Sarah, President and CEO

How to read Form 4 transaction codes