Sophie McCallum - 01 Oct 2025 Form 4 Insider Report for Deep Isolation Nuclear, Inc.

Role: Chief of Staff, Corp. Sec.
Signature: /s/ Sophie McCallum
Transactions as of: 01 Oct 2025
Transactions value $: $0
Form type: 4
Filing time: 03 Oct 2025, 16:16:05 UTC
Previous filing: 09 Sep 2025
Next filing: 21 Nov 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
McCallum Sophie	Chief of Staff, Corp. Sec.	C/O DEEP ISOLATION NUCLEAR, INC., 2001 ADDISON STREET, SUITE 300, BERKELEY	/s/ Sophie McCallum	03 Oct 2025	0002085363

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction		Common Stock	Award	$0	+9.87K		$0.00	9.87K	01 Oct 2025	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction		Stock Option (Right to Buy)	Award	$0	+29.6K		$0.00	29.6K	01 Oct 2025	Common Shares	29.6K	$3.00	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents the grant of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. The RSUs are subject to a 4-year vesting period, whereby 1/48th of the RSUs will vest monthly beginning October 1, 2025, subject to the Reporting Person's continuous service through each vesting date.
F2	The Stock Option is subject to a 4-year vesting schedule, whereby 1/48th of the option shares will vest monthly beginning on October 1, 2025, subject to Reporting Person's continued service through each vesting date.