Diamondback director plans $210K stock sale

Rhea-AI Filing Summary

Diamondback Energy, Inc. (FANG) director Mark Lawrence Plaumann has filed a notice of proposed sale under Rule 144 for up to 1,000 shares of common stock held at Charles Schwab & Co., Inc., with an indicated aggregate market value of $210,577.00 and an intended sale date of 08/21/2026. These shares were acquired through equity compensation via restricted stock lapses between 2018 and 2020. In the prior three months, Plaumann sold 500 shares for total proceeds of $98,250.00.

Key Figures

Shares proposed to be sold: 1,000 shares of common stock Aggregate market value of proposed sale: $210,577.00 Intended sale date: 08/21/2026 +3 more

6 metrics

Shares proposed to be sold 1,000 shares of common stock Proposed sale under Rule 144 by director Mark Lawrence Plaumann

Aggregate market value of proposed sale $210,577.00 Value associated with 1,000 shares proposed for sale

Intended sale date 08/21/2026 Planned date for Rule 144 sale of 1,000 shares

Shares sold in past 3 months 500 shares Shares sold on 06/09/2026 by Mark Lawrence Plaumann

Aggregate proceeds from past 3‑month sale $98,250.00 Sale of 500 shares on 06/09/2026

Equity compensation components 100, 787, 113 shares Restricted stock lapses on 07/01/2018, 06/06/2019, 06/03/2020

Key Terms

Rule 144, Restricted Stock Lapse, Equity Compensation, Aggregate market value

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Restricted Stock Lapse financial

"Common | 07/01/2018 | Restricted Stock Lapse | Diamondback Energy, Inc."

Equity Compensation financial

"100 | 07/01/2018 | Equity Compensation"

Equity compensation is pay given to employees, executives or contractors in the form of company ownership—such as stock, stock options or restricted shares—rather than just cash. It matters to investors because it can align workers' incentives with shareholders (like paying someone in slices of the same pie they help grow), but it also increases the number of shares outstanding and company expenses, affecting ownership percentages and earnings per share.

Aggregate market value financial

"Common | ... | 1000 | 210577.00 | ..."

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

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

What does the Form 144 filing by FANG director Mark Lawrence Plaumann disclose?

It discloses that director Mark Lawrence Plaumann intends to sell 1,000 shares of Diamondback Energy, Inc. (FANG) common stock under Rule 144, with an indicated aggregate market value of $210,577.00 and a planned sale date of 08/21/2026.

How many FANG shares has Mark Lawrence Plaumann sold recently?

Over the past three months, Mark Lawrence Plaumann sold 500 shares of Diamondback Energy, Inc. common stock on 06/09/2026 for total proceeds of $98,250.00, according to the Form 144 disclosure.

How were the Diamondback Energy (FANG) shares to be sold under Form 144 originally acquired?

The 1,000 shares proposed for sale were acquired as equity compensation through restricted stock lapses on 07/01/2018 (100 shares), 06/06/2019 (787 shares), and 06/03/2020 (113 shares).

What is the aggregate market value of the FANG shares covered by this Form 144?

The Form 144 lists an aggregate market value of $210,577.00 for the 1,000 shares of Diamondback Energy, Inc. common stock that Mark Lawrence Plaumann intends to sell through Charles Schwab & Co., Inc.

On which market is the Diamondback Energy (FANG) stock in this Form 144 indicated to trade?

The Form 144 identifies the common stock as trading on NASDAQ in connection with Mark Lawrence Plaumann’s proposed sale of 1,000 shares of Diamondback Energy, Inc. common stock.

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

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Available on EDGAR 08/21/2026 - 04:06 PM Accepted by SEC EDGAR 08/21/2026 - 04:05 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001290795
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Diamondback Energy, Inc.
SEC File Number	001-35700
Address of Issuer	500 WEST TEXAS AVENUE SUITE 100 MIDLAND TEXAS 79701
Phone	432-221-7400
Name of Person for Whose Account the Securities are To Be Sold	Plaumann Mark Lawrence
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Charles Schwab & Co., Inc. 3000 Schwab Way Westlake TX 76262	1000	210577.00	280024353	08/21/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	07/01/2018	Restricted Stock Lapse	Diamondback Energy, Inc.			100	07/01/2018	Equity Compensation
Common	06/06/2019	Restricted Stock Lapse	Diamondback Energy, Inc.			787	06/06/2019	Equity Compensation
Common	06/03/2020	Restricted Stock Lapse	Diamondback Energy, Inc.			113	06/03/2020	Equity Compensation

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
MARK LAWRENCE PLAUMANN 500 WEST TEXAS AVENUE SUITE 100 MIDLAND TX 79701	Diamondback Energy, Inc.	06/09/2026	500	98250.00

144: Remarks and Signature

Remarks
Date of Notice	08/21/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	MARK LAWRENCE PLAUMANN
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)