Bolt Biotherapeutics CEO sells 17,566 shares

Bolt Biotherapeutics’ President, CEO and CFO reported small ESPP share purchases and tax-withholding-related stock sales in 2026.

Rhea-AI Filing Summary

Bolt Biotherapeutics, Inc. (BOLT) reported that President, CEO and CFO William P. Quinn sold company common stock on three days in September 2026 and made one earlier purchase in June 2026. The September sales, totaling 17,566 shares, were made at weighted average prices and, per footnotes, were to cover tax withholding obligations upon vesting of restricted stock units granted on October 22, 2025. On June 5, 2026, he acquired 637 shares through the company’s Employee Stock Purchase Plan in a transaction exempt under Rule 16b-3(c). No Rule 10b5-1 trading plan is reported.

Insider Trade Summary

Net Seller: 16,929 shares

Net Sell 4 txns

Insider Quinn William P.

Role President, CEO and CFO

Bought 637 shs ($2K)

Sold 17,566 shs ($58K)

Type	Security	Shares	Price	Value
Sale	Common Stock F4	9,132	$3.2364	$30K
Sale	Common Stock F3	6,545	$3.3183	$22K
Sale	Common Stock F2	1,889	$3.774	$7K
Purchase	Common Stock F1	637	$3.876	$2K

Holdings After Transaction: Common Stock — 25,384 shares (Direct)

Footnotes (4)

1. F1. These shares were acquired under the Issuer's Employee Stock Purchase Plan in transactions that were exempt under Rule 16b-3(c).
2. F2. Represents weighted average sales price. These shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of the restricted stock units granted on October 22, 2025. The shares were sold at prices ranging from $3.60 to $4.14. The Reporting Person will provide upon request, to the Securities and Exchange Commission (the "SEC"), the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.
3. F3. Represents weighted average sales price. These shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of the restricted stock units granted on October 22, 2025. The shares were sold at prices ranging from $3.22 to $3.67. The Reporting Person will provide upon request, to the Securities and Exchange Commission (the "SEC"), the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.
4. F4. Represents weighted average sales price. These shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of the restricted stock units granted on October 22, 2025. The shares were sold at prices ranging from $3.15 to $3.41. The Reporting Person will provide upon request, to the Securities and Exchange Commission (the "SEC"), the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

Key Figures

Shares sold September 18, 2026: 9,132 shares at $3.2364 per share Shares sold September 17, 2026: 6,545 shares at $3.3183 per share Shares sold September 16, 2026: 1,889 shares at $3.7740 per share +3 more

6 metrics

Shares sold September 18, 2026 9,132 shares at $3.2364 per share Open market or private sale of Bolt Biotherapeutics common stock

Shares sold September 17, 2026 6,545 shares at $3.3183 per share Open market or private sale of Bolt Biotherapeutics common stock

Shares sold September 16, 2026 1,889 shares at $3.7740 per share Open market or private sale of Bolt Biotherapeutics common stock

Shares purchased June 5, 2026 637 shares at $3.8760 per share Acquired under the Issuer's Employee Stock Purchase Plan

Total shares sold in September 2026 17,566 shares Aggregate of three sale transactions reported for September 16–18, 2026

Net shares sold (sales minus purchases) 16,929 shares Net of 17,566 shares sold and 637 shares purchased across all reported transactions

Key Terms

Employee Stock Purchase Plan, Rule 16b-3(c), restricted stock units, weighted average sales price, +1 more

5 terms

Employee Stock Purchase Plan financial

"These shares were acquired under the Issuer's Employee Stock Purchase Plan"

An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.

Rule 16b-3(c) regulatory

"transactions that were exempt under Rule 16b-3(c)"

An SEC rule that lets corporate insiders avoid automatic "short‑swing" profit recovery when they buy or sell their company’s stock under a pre‑approved, written plan that meets specific conditions. For investors, it matters because it clarifies when insider trades are treated as routine, reducing legal uncertainty and helping distinguish trades made for ordinary compensation or pre‑planned reasons from those that might signal opportunistic or timely insider advantage.

restricted stock units financial

"in connection with the vesting of the restricted stock units granted"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

weighted average sales price financial

"Represents weighted average sales price. These shares were sold"

tax withholding obligations financial

"sold by the reporting person to cover tax withholding obligations"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did BOLT’s CEO William P. Quinn report in this Form 4?

He reported three sales totaling 17,566 shares of Bolt Biotherapeutics common stock on September 16–18, 2026, and a purchase of 637 shares on June 5, 2026, under the company’s Employee Stock Purchase Plan.

Were William P. Quinn’s September 2026 BOLT stock sales discretionary sales?

The filing states the September 2026 sales were made to cover tax withholding obligations related to vesting restricted stock units granted on October 22, 2025, and gives weighted average prices with price ranges for each sale date.

At what prices did BOLT’s CEO sell shares in September 2026?

The shares were sold at weighted average prices of about $3.77 per share on September 16, $3.32 on September 17, and $3.24 on September 18, 2026, with actual trade prices in ranges disclosed in the footnotes.

How many BOLT shares did William P. Quinn buy through the ESPP in 2026?

On June 5, 2026, he acquired 637 shares of Bolt Biotherapeutics common stock at $3.876 per share under the Issuer’s Employee Stock Purchase Plan, in a transaction exempt under Rule 16b-3(c).

Is a Rule 10b5-1 trading plan disclosed for these BOLT insider transactions?

No. The Form 4 indicates no Rule 10b5-1 plan, and the footnotes describe the September 2026 sales as covering tax withholding, and the June 2026 purchase as under the Employee Stock Purchase Plan.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/21/2026 - 06:04 PM Accepted by SEC EDGAR 09/21/2026 - 06:03 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Quinn William P.

(Last) (First) (Middle)

C/O BOLT BIOTHERAPEUTICS, INC.

900 CHESAPEAKE DRIVE

(Street)

REDWOOD CITY CALIFORNIA 94063

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Bolt Biotherapeutics, Inc. [ BOLT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President, CEO and CFO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/16/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	06/05/2026		P(1)		637	A	$3.876	2,950	D
Common Stock	09/16/2026		S		1,889	D	$3.774(2)	41,061	D
Common Stock	09/17/2026		S		6,545	D	$3.3183(3)	34,516	D
Common Stock	09/18/2026		S		9,132	D	$3.2364(4)	25,384	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. These shares were acquired under the Issuer's Employee Stock Purchase Plan in transactions that were exempt under Rule 16b-3(c).

2. Represents weighted average sales price. These shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of the restricted stock units granted on October 22, 2025. The shares were sold at prices ranging from $3.60 to $4.14. The Reporting Person will provide upon request, to the Securities and Exchange Commission (the "SEC"), the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

3. Represents weighted average sales price. These shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of the restricted stock units granted on October 22, 2025. The shares were sold at prices ranging from $3.22 to $3.67. The Reporting Person will provide upon request, to the Securities and Exchange Commission (the "SEC"), the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

4. Represents weighted average sales price. These shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of the restricted stock units granted on October 22, 2025. The shares were sold at prices ranging from $3.15 to $3.41. The Reporting Person will provide upon request, to the Securities and Exchange Commission (the "SEC"), the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

	/s/ William P. Quinn	09/21/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)