Form 8-K

8-K — Core Natural Resources, Inc.

Accession: 0001193125-26-356186

Filed: 2026-08-19

Period: 2026-08-18

CIK: 0001710366

SIC: 1220 (BITUMINOUS COAL & LIGNITE MINING)

Item: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): August 18, 2026

Core Natural Resources, Inc.

(Exact name of registrant as specified in its charter)

Delaware

001-38147

82-1954058

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

275 Technology Drive Suite 101

Canonsburg, Pennsylvania 15317

(Address of principal executive offices)

(Zip code)

Registrant’s telephone number, including area code:

(724) 416-8300

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

Symbol(s)

Name of each exchange

on which registered

Common Stock, $0.01 par value

CNR

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.02

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On August 18, 2026, as part of its long-term succession process, the Board of Directors (the “Board”) of Core Natural Resources, Inc. (the “Company”) appointed Nathan Tucker to serve as the Company’s Senior Vice President and Chief Financial Officer, effective immediately, taking over the Chief Financial Officer role from Mitesh Thakkar, who will continue to serve as President of the Company and is assuming an expanded role with day-to-day responsibility for the Company’s primary operating functions, including operations, marketing, logistics, and long-term strategy.

Mr. Tucker, age 39, has served as the Company’s vice president of finance since the Company’s formation in January 2025 via the merger of CONSOL Energy Inc. (“CONSOL”) and Arch Resources, Inc. He previously served as director of finance and investor relations for CONSOL from 2020 until January 2025 after joining CONSOL in 2010.

In connection with Mr. Tucker’s appointment, the Board approved a new compensation package for Mr. Tucker to increase his annual base salary to $400,000, his target short-term incentive compensation opportunity to 65% of his annual base salary, and his long-term incentive compensation opportunity to 125% of his annual base salary.

Mr. Tucker also received a severance agreement (the “Severance Agreement”) in connection with his appointment, which contains substantially the same terms and conditions as the severance agreements entered into with the Company’s other executive officers.

The foregoing description of the Severance Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the form severance agreement, which was filed as Exhibit 10.72 with the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Item 7.01

Regulation FD Disclosure.

On August 19, 2026, the Company issued a press release announcing its executive succession plan and the appointment of Mr. Tucker as the Company’s Senior Vice President and Chief Financial Officer, which is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

The information contained in this Item 7.01 and Exhibit 99.1 shall be considered “furnished” and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, nor shall it be deemed incorporated by reference into any reports or filings with the Securities and Exchange Commission, whether made before or after the date hereof, except as expressly set forth by specific reference in such a filing.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.

Description

99.1

Press Release of Core Natural Resources, Inc. dated August 19, 2026.

104

Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Core Natural Resources, Inc.

(Registrant)

By:

/s/ Rosemary L. Klein

Rosemary L. Klein

Senior Vice President, Chief Legal Officer and Corporate Secretary

Dated: August 19, 2026

EX-99.1

Filename: d113945dex991.htm · Sequence: 2

EX-99.1

Exhibit 99.1

Core Natural Resources Advances its Executive Succession Plan

Thakkar assumes day-to-day responsibility for

Core’s primary operating functions

Tucker succeeds Thakkar as Core’s chief financial officer

CANONSBURG, Pa., August 19, 2026 /PRNewswire/ — Today, Core Natural Resources, Inc. (NYSE: CNR) (“Core” or the “company”)

announced that – as part of its long-term succession process – Core’s president, Mitesh Thakkar, is assuming an expanded role within the organization, with

day-to-day responsibility for the company’s primary operating functions, including operations, marketing, logistics, and long-term strategy, effective immediately.

“On behalf of the entire board, I want to congratulate Mitesh on this long-planned and well-deserved expansion of his responsibilities,” said

Jimmy Brock, Core’s chairman and CEO. “The board views Mitesh as the ideal person to lead Core’s day-to-day endeavors at this exciting time in the

company’s development and growth. Mitesh is a proven leader and strategic thinker with an exceptional track record across a range of critical functions, and I look forward to continuing to work closely with him to unlock Core’s full

potential.”

As part of this transition, the board also announced the election of Nathan Tucker as Core’s senior vice president and chief

financial officer, effective immediately.

“Nate has distinguished himself as a strong and effective leader with exceptional financial acumen and a

keen understanding of Core’s business, and I am confident he will excel in this important role,” said Brock.

“Nate will do an excellent

job leading Core’s highly talented finance and accounting team,” said Thakkar. “I look forward to working closely with him as we seek to drive exceptional future value for our stockholders.”

Thakkar had served as Core’s president and chief financial officer since the company’s formation in January 2025. Prior to that time, he had held

the position of senior vice president and chief financial officer of CONSOL Energy Inc. (“CONSOL”) – one of Core’s predecessor companies – since 2020. Thakkar joined CONSOL in 2015 after beginning his career as an

equity analyst with FBR Capital Markets (now part of B. Riley FBR, Inc.).

Tucker had served as Core’s vice president of finance since the

company’s formation. He had previously served as director of finance and investor relations for CONSOL from 2020 until January 2025 after joining CONSOL in 2010.

About Core Natural Resources, Inc.

Core Natural

Resources, Inc. (NYSE: CNR) is a world-class producer of high-quality metallurgical and high calorific value thermal coals for the global marketplace. Core’s highly skilled workforce operates a best-in-sector portfolio of large-scale, low-cost longwall mines, including the Pennsylvania Mining Complex, Leer, Leer South, and West Elk mines, along with one of the

world’s largest and most productive surface mines, Black Thunder. The company plays an essential role in meeting the world’s growing need for steel, infrastructure, and energy, while simultaneously serving the resurgent requirements of

the U.S. power generation fleet. Core has an extensive and strategic logistical network – anchored by ownership positions in two East Coast marine export terminals – that provides reliable and efficient access to seaborne coal markets.

The company’s deeply ingrained culture is grounded in safety and compliance, continuous improvement, and financial performance, with an emphasis on stakeholder engagement and stockholder returns. Core was created in January 2025 via the merger

of long-time industry leaders CONSOL Energy and Arch Resources and is based in Canonsburg, Pennsylvania.

Cautionary Statement Regarding Forward-Looking Statements

This communication contains certain “forward-looking statements” within the meaning of federal securities laws. Forward-looking statements may

be identified by words such as “years ahead,” “look forward” and similar expressions. Forward-looking statements are not statements of historical fact and reflect Core’s current views about future events. No assurances

can be given that the forward-looking statements contained in this communication will occur as projected, and actual results may differ materially from those projected. Forward-looking statements are based on current expectations, estimates and

assumptions that involve a number of risks and uncertainties that could cause actual results to differ materially from those projected. These risks and uncertainties include, without limitation, uncertainties regarding the ability of Core to mine,

upgrade, process, and extract rare earth elements and critical minerals from its existing mines, including uncertainties regarding the financial impacts of such activities; risks related to the prior occurrence of combustion-related activity at

Core’s Leer South mine and the risk of future occurrences; the increase in combustion-related gases at Core’s Leer South mine; deterioration in economic conditions or changes in consumption patterns of our customers may decrease demand

for our products, impair our ability to collect customer receivables and impair our ability to access capital; volatility and wide fluctuation in coal prices based upon a number of factors beyond our control; an extended decline in the prices we

receive for our coal; significant downtime of our equipment or inability to obtain equipment, parts or raw materials; decreases in the availability of, or increases in the price of, commodities or capital equipment used in our coal mining

operations; our reliance on major customers, our ability to collect payment from our customers and uncertainty in connection with our customer contracts; our inability to acquire additional coal reserves or resources that are economically

recoverable; decreases in coal consumption patterns for steel production, electric power generation and industrial applications; the availability and reliability of transportation facilities and other systems that deliver our coal to market and

fluctuations in transportation costs; a loss of our competitive position; inflation that could result in higher costs and decreased profitability; foreign currency fluctuations that could adversely affect the competitiveness of our coal abroad;

risks related to the fact that a significant portion of our production is sold in international markets (and may grow) and our compliance with export control and anti-corruption laws; coal users switching to other fuels in order to comply with

various environmental standards related to coal combustion emissions; the impact of current and future regulations to address climate change, the discharge, disposal and clean-up of hazardous substances and

wastes and employee health and safety on our operating costs as well as on the market for coal; the risks inherent in coal operations, including being subject to unexpected disruptions caused by adverse geological conditions, equipment failure,

delays in moving longwall equipment, railroad derailments or strikes, security breaches or terroristic acts and other hazards, delays in the completion of significant construction or repair of equipment, fires, explosions, seismic activities,

accidents and weather conditions; failure to obtain or renew surety bonds, letters of credit or insurance coverages on acceptable terms; the effects of coordinating our operations with oil and natural gas drillers and distributors operating on our

land; our inability to obtain financing for capital expenditures on satisfactory terms; the effects of our securities being excluded from certain investment funds as a result of environmental, social and corporate governance practices; the effects

of global conflicts on commodity prices and supply chains; the effect of new or existing laws, regulations, tariffs, executive orders or other trade measures; our inability to find suitable joint venture partners, acquisition targets or similar

investments or integrating the operations of future acquisitions or investments into our operations; obtaining, maintaining and renewing governmental permits and approvals for our coal operations; the effects of asset retirement obligations,

employee-related long-term liabilities and certain other liabilities; uncertainties in estimating our economically recoverable coal reserves; defects in our chain of title for our undeveloped reserves or failure to acquire additional property to

perfect our title to coal rights; the outcomes of various legal proceedings; the risk of our debt agreements, our debt and changes in interest rates affecting our operating results and cash flows; information theft, data corruption, operational

disruption and/or financial loss resulting from a terrorist attack or cyber incident; the potential failure to retain and attract qualified personnel of the company; failure to maintain effective internal control over financial reporting;

uncertainty with respect to the company’s common stock, potential stock price volatility and future dilution; uncertainty regarding the timing and value of any dividends we may declare; uncertainty as to whether we will repurchase shares of

our common stock; inability of stockholders to bring legal action against us in any forum other than the state courts of Delaware; the risk that the businesses of the company and Arch Resources, Inc. will not be integrated successfully after the

closing of the merger; the risk that the anticipated benefits of the Merger may not be realized or may take longer to realize than expected; and other unforeseen factors.

All such factors are difficult to predict, are beyond Core’s control, and are subject to additional

risks and uncertainties, including those detailed in Core’s annual report on Form 10-K for the year ended December 31, 2025, quarterly reports on Form 10-Q,

and current reports on Form 8-K that are available on Core’s website at www.corenaturalresources.com and on the SEC’s website at http://www.sec.gov.

Forward-looking statements are based on the estimates and opinions of management at the time the statements are made. Core does not undertake any

obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. Readers are cautioned not to place undue reliance on these forward-looking statements that

speak only as of the date hereof.

Source: Core Natural Resources, Inc.

Contacts:

Investor:

Deck Slone, (314) 994-2766

investorrelations@coreresources.com

Media:

Erica Fisher, (724) 416-8292

media@coreresources.com

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