Bolt Biotherapeutics COO sells 13,176 shares

Bolt Biotherapeutics’ COO reported selling 13,176 shares primarily to cover RSU-related tax withholding.

Rhea-AI Filing Summary

Bolt Biotherapeutics, Inc. (BOLT) reported that Chief Operating Officer Grant Yonehiro sold a total of 13,176 shares of Common Stock in three transactions on September 16–18, 2026. The company states these sales were made to cover tax withholding obligations arising from the vesting of restricted stock units granted on October 22, 2025.

The transactions were open-market or private sales at weighted average prices of $3.7740, $3.3183, and $3.2364 per share, with actual prices in specified ranges. No Rule 10b5-1 trading plan is reported, and resulting share holdings are not stated in this filing.

Insider Trade Summary

Net Seller: 13,176 shares

Net Sell 3 txns

Insider Yonehiro Grant

Role Chief Operating Officer

Sold 13,176 shs ($44K)

Type	Security	Shares	Price	Value
Sale	Common Stock F3	6,850	$3.2364	$22K
Sale	Common Stock F2	4,909	$3.3183	$16K
Sale	Common Stock F1	1,417	$3.774	$5K

Holdings After Transaction: Common Stock — 17,269 shares (Direct)

Footnotes (3)

1. F1. 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.
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 $3.22 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.
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 $3.15 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

Total shares sold: 13,176 shares Shares sold September 16, 2026: 1,417 shares at $3.7740 weighted average price Shares sold September 17, 2026: 4,909 shares at $3.3183 weighted average price +2 more

5 metrics

Total shares sold 13,176 shares Aggregate of three sales reported for September 16–18, 2026

Shares sold September 16, 2026 1,417 shares at $3.7740 weighted average price Open-market or private sale; prices ranged $3.60–$4.14

Shares sold September 17, 2026 4,909 shares at $3.3183 weighted average price Open-market or private sale; prices ranged $3.22–$3.67

Shares sold September 18, 2026 6,850 shares at $3.2364 weighted average price Open-market or private sale; prices ranged $3.15–$3.41

RSU grant date October 22, 2025 Restricted stock units whose vesting triggered tax withholding sales

Key Terms

weighted average sales price, restricted stock units, tax withholding obligations, open market or private transaction

4 terms

weighted average sales price financial

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

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.

tax withholding obligations financial

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

open market or private transaction financial

"Sale in open market or private transaction"

FAQ

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

What insider transactions did BOLT report for COO Grant Yonehiro?

Bolt Biotherapeutics reported that COO Grant Yonehiro sold a total of 13,176 shares of Common Stock in three transactions on September 16, 17, and 18, 2026, all described as sales to cover tax withholding obligations from vesting restricted stock units.

How many BOLT shares did the COO sell on each date?

On September 16, 2026, 1,417 shares were sold; on September 17, 2026, 4,909 shares were sold; and on September 18, 2026, 6,850 shares were sold, for a total of 13,176 shares of Bolt Biotherapeutics Common Stock.

What prices were received in the BOLT share sales by the COO?

The filing reports weighted average sale prices of $3.7740, $3.3183, and $3.2364 per share. Footnotes state the actual sale prices ranged from $3.60–$4.14, $3.22–$3.67, and $3.15–$3.41, respectively.

Why did the BOLT COO sell these shares?

The company states the shares were sold by the reporting person to cover tax withholding obligations in connection with the vesting of restricted stock units that were granted on October 22, 2025.

Were the BOLT COO’s sales made under a Rule 10b5-1 trading plan?

No. The filing’s Rule 10b5-1 checkbox is not marked as an affirmative plan, and the footnotes describing the transactions do not state that they were made pursuant to any Rule 10b5-1 trading plan.

Does the Form 4 state the COO’s remaining BOLT share holdings after these sales?

No. For each transaction, the field for shares owned following the transaction is not filled in, so this Form 4 does not state the COO’s post-transaction holdings in Bolt Biotherapeutics stock.

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

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 09/21/2026 - 06:06 PM Accepted by SEC EDGAR 09/21/2026 - 06:05 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^*

Yonehiro Grant

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Operating Officer

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	09/16/2026		S		1,417	D	$3.774(1)	29,028	D
Common Stock	09/17/2026		S		4,909	D	$3.3183(2)	24,119	D
Common Stock	09/18/2026		S		6,850	D	$3.2364(3)	17,269	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. 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.

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 $3.22 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.

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 $3.15 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, Attorney-in-Fact	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)