STOCK TITAN

Standard Nuclear (STDN) COO discloses 3M shares and 760,338 stock options

(Neutral)
(Neutral)
Form Type
3

Rhea-AI Filing Summary

Standard Nuclear, Inc.’s chief operating officer, Marrocco Keeley Rose, reports direct ownership of 3,000,000 shares of Class A common stock. This includes 840,000 regular shares and 2,160,000 shares pursuant to a restricted stock award. Rose also holds an incentive stock option granted on January 11, 2026 to purchase 760,338 shares of Class A common stock at an exercise price of $0.60 per share, expiring January 10, 2036. The option vests 25% on January 1, 2027, then 1/48th monthly, with an additional 10% vesting upon the closing of the company’s initial public offering, in each case subject to continued service.

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Insider Marrocco Keeley Rose
Role Chief Operating Officer
Type Security Shares Price Value
holding Incentive stock options F2 -- -- --
holding Class A common stock F1 -- -- --
Holdings After Transaction: Incentive stock options — 760,338 shares (Direct); Class A common stock — 3,000,000 shares (Direct)
Footnotes (2)
  1. F1. Includes (a) 840,000 shares of Class A Common Stock and (b) 2,160,000 shares of Class A Common Stock pursuant to a restricted stock award.
  2. F2. Represents a stock option to purchase 760,338 shares of Class A Common Stock granted on January 11, 2026 with an exercise price of $0.60 per share, which vests as follows: 25% vests on January 1, 2027, with an additional 1/48th vesting monthly thereafter, and with 10% of the total number of shares subject to the option vesting and becoming exercisable upon the closing of the Issuer's initial public offering, in each case subject to the Reporting Person's continued service.
Direct Class A shares held 3,000,000 shares Total direct Class A common stock reported by COO Marrocco Keeley Rose
Regular Class A shares 840,000 shares Portion of direct holdings not pursuant to restricted stock
Restricted stock award shares 2,160,000 shares Class A common stock issued pursuant to a restricted stock award
Option underlying shares 760,338 shares Shares of Class A common stock underlying incentive stock option
Exercise price $0.60 per share Exercise price of incentive stock option granted January 11, 2026
Option expiration 2036-01-10 Expiration date of the incentive stock option
Initial cliff vesting 25% Portion of option vesting on January 1, 2027
IPO vesting tranche 10% of shares Portion of option vesting upon closing of initial public offering
restricted stock award financial
"2,160,000 shares of Class A Common Stock pursuant to a restricted stock award"
A restricted stock award is company shares given to an employee or executive that cannot be sold or fully owned until certain conditions—like staying with the company for a set time or hitting performance targets—are met. Think of it as a gift that only becomes yours after you fulfill specific obligations; for investors, these awards matter because they can increase the total shares outstanding when they vest, reveal how management is being paid and motivated, and create potential selling pressure when restrictions lift.
Incentive stock options financial
"security_title: Incentive stock options"
Incentive stock options are a type of employee stock option that gives eligible workers the right to buy company shares at a fixed price later on, often below future market value. They matter to investors because they align employee incentives with company performance, can dilute existing ownership when exercised, and create potential tax advantages for option holders if certain holding-time rules are met — think of them as a coupon to buy stock at today’s price with extra tax rules attached.
exercise price financial
"exercise price of $0.60 per share, which vests as follows"
The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.
initial public offering financial
"vesting and becoming exercisable upon the closing of the Issuer's initial public offering"
An initial public offering (IPO) is when a private company first sells its shares to the public and becomes a stock-listed company. It matters because it allows the company to raise money from a wide range of investors, helping it grow, while giving early shareholders a way to sell some of their ownership.

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

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FAQ

What insider position did Standard Nuclear (STDN) report for Marrocco Keeley Rose?

Standard Nuclear’s chief operating officer, Marrocco Keeley Rose, reported direct ownership of 3,000,000 shares of Class A common stock. This disclosure establishes Rose’s initial reported equity position as an executive of the company.

How many Standard Nuclear (STDN) Class A shares does the COO directly hold?

The COO, Marrocco Keeley Rose, directly holds 3,000,000 Class A common shares. This consists of 840,000 regular shares plus 2,160,000 shares issued pursuant to a restricted stock award, all reported as direct ownership.

What stock options for STDN does Marrocco Keeley Rose hold and at what price?

Marrocco Keeley Rose holds an incentive stock option covering 760,338 shares of Class A common stock at an exercise price of $0.60 per share. The option was granted on January 11, 2026 and expires on January 10, 2036.

How do the STDN stock options for the COO vest over time?

The option for 760,338 STDN shares vests 25% on January 1, 2027, with an additional 1/48th vesting monthly thereafter. Another 10% of the total shares vest and become exercisable upon closing of Standard Nuclear’s initial public offering, subject to continued service.

What portion of the COO’s STDN holdings are restricted stock awards?

Out of 3,000,000 directly held Class A shares, 2,160,000 are issued pursuant to a restricted stock award. The remaining 840,000 shares are regular Class A common stock, all reported as directly owned by Marrocco Keeley Rose.
SEC Form 3
FORM 3UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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:3235-0104
Estimated average burden
hours per response:0.5
1. Name and Address of Reporting Person*
Marrocco Keeley Rose

(Last)(First)(Middle)
C/O STANDARD NUCLEAR, INC.
200 EUROPIA AVE

(Street)
OAK RIDGE TENNESSEE 37830

(City)(State)(Zip)

UNITED STATES

(Country)
2. Date of Event Requiring Statement (Month/Day/Year)
07/15/2026
3. Issuer Name and Ticker or Trading Symbol
Standard Nuclear, Inc. [ STDN ]
3a. Foreign Trading Symbol
5. If Amendment, Date of Original Filed (Month/Day/Year)
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Chief Operating Officer
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Class A common stock3,000,000(1)D
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year)3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date ExercisableExpiration DateTitleAmount or Number of Shares
Incentive stock options (2)01/10/2036Class A common stock760,338$0.6D
Explanation of Responses:
1. Includes (a) 840,000 shares of Class A Common Stock and (b) 2,160,000 shares of Class A Common Stock pursuant to a restricted stock award.
2. Represents a stock option to purchase 760,338 shares of Class A Common Stock granted on January 11, 2026 with an exercise price of $0.60 per share, which vests as follows: 25% vests on January 1, 2027, with an additional 1/48th vesting monthly thereafter, and with 10% of the total number of shares subject to the option vesting and becoming exercisable upon the closing of the Issuer's initial public offering, in each case subject to the Reporting Person's continued service.
Remarks:
/s/ Keeley Marrocco07/15/2026
** Signature of Reporting PersonDate
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 5 (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 3: SEC 1473 (03-26)