Filed by Exxon Mobil Corporation

(Commission File No.: 001-02256)

Pursuant to Rule 425 of the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

of the Securities Exchange Act of 1934

Subject Company: Pioneer Natural Resources Company

(Commission File No.: 001-13245)

The following communication was posted on Instagram, by Exxon Mobil Corporation on October 11, 2023:

Important Information about the Transaction and Where to Find It

In connection with the proposed transaction between Exxon Mobil Corporation (“ExxonMobil”) and Pioneer Natural Resources Company (“Pioneer”), ExxonMobil and Pioneer will file relevant materials with the Securities and Exchange Commission (the “SEC”), including a registration statement on Form S-4 filed by ExxonMobil that will include a proxy statement of Pioneer that also constitutes a prospectus of ExxonMobil. A definitive proxy statement/prospectus will be mailed to stockholders of Pioneer. This communication is not a substitute for the registration statement, proxy statement or prospectus or any other document that ExxonMobil or Pioneer (as applicable) may file with the SEC in connection with the proposed transaction. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, INVESTORS AND SECURITY HOLDERS OF EXXONMOBIL AND PIONEER ARE URGED TO READ THE

REGISTRATION STATEMENT, THE PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT ARE FILED OR WILL BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND RELATED MATTERS. Investors and security holders may obtain free copies of the registration statement and the proxy statement/prospectus (when they become available), as well as other filings containing important information about ExxonMobil or Pioneer, without charge at the SEC’s Internet website (http://www.sec.gov). Copies of the documents filed with the SEC by ExxonMobil will be available free of charge under the tab “SEC Filings” on the “Investors” page of ExxonMobil’s internet website at www.exxonmobil.com or by contacting ExxonMobil’s Investor Relations Department at investor.relations@exxonmobil.com. Copies of the documents filed with the SEC by Pioneer will be available free of charge on Pioneer’s internet website at https:// investors.pxd.com/investors/financials/sec-filings/. The information included on, or accessible through, ExxonMobil’s or Pioneer’s website is not incorporated by reference into this communication.

Participants in the Solicitation

ExxonMobil, Pioneer, their respective directors and certain of their respective executive officers may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information about the directors and executive officers of Pioneer is set forth in its proxy statement for its 2023 annual meeting of stockholders, which was filed with the SEC on April 13, 2023, in its Form 10-K for the year ended December 31, 2022, which was filed with the SEC on February 23, 2023, in its Form 8-K filed on May 30, 2023, in its Form 8-K filed on April 26, 2023 and in its Form 8-K filed on February 13, 2023. Information about the directors and executive officers of ExxonMobil is set forth in its proxy statement for its 2023 annual meeting of stockholders, which was filed with the SEC on April 13, 2023, in its Form 10-K for the year ended December 31, 2022, which was filed with the SEC on February 22, 2023, in its Form 8-K filed on June 6, 2023 and in its Form 8-K filed on February 24, 2023. Additional information regarding the participants in the proxy solicitations and a description of their direct or indirect interests, by security holdings or otherwise, will be contained in the proxy statement/prospectus and other relevant materials filed with the SEC when they become available.

No Offer or Solicitation

This communication is for informational purposes and is not intended to, and shall not, constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, nor shall there be any offer, solicitation or sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as amended.

Forward-Looking Statements

This communication contains “forward-looking statements” within the meaning of the federal securities laws, including Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In this context, forward-looking statements often address future business and financial events, conditions, expectations, plans or

ambitions, and often contain words such as “expect,” “anticipate,” “intend,” “plan,” “believe,” “seek,” “see,” “will,” “would,” “target,” similar expressions, and variations or negatives of these words, but not all forward-looking statements include such words. Forward-looking statements by their nature address matters that are, to different degrees, uncertain, such as statements about the consummation of the proposed transaction and the anticipated benefits thereof. All such forward-looking statements are based upon current plans, estimates, expectations and ambitions that are subject to risks, uncertainties and assumptions, many of which are beyond the control of ExxonMobil and Pioneer, that could cause actual results to differ materially from those expressed in such forward-looking statements. Important risk factors that may cause such a difference include, but are not limited to: the completion of the proposed transaction on anticipated terms and timing, or at all, including obtaining regulatory approvals that may be required on anticipated terms and Pioneer stockholder approval; anticipated tax treatment, unforeseen liabilities, future capital expenditures, revenues, expenses, earnings, synergies, economic performance, indebtedness, financial condition, losses, future prospects, business and management strategies for the management, expansion and growth of the combined company’s operations and other conditions to the completion of the proposed transaction, including the possibility that any of the anticipated benefits of the proposed transaction will not be realized or will not be realized within the expected time period; the ability of ExxonMobil and Pioneer to integrate the business successfully and to achieve anticipated synergies and value creation; potential litigation relating to the proposed transaction that could be instituted against ExxonMobil, Pioneer or their respective directors; the risk that disruptions from the proposed transaction will harm ExxonMobil’s or Pioneer’s business, including current plans and operations and that management’s time and attention will be diverted on transaction-related issues; potential adverse reactions or changes to business relationships resulting from the announcement or completion of the proposed transaction; rating agency actions and ExxonMobil and Pioneer’s ability to access short- and long-term debt markets on a timely and affordable basis; legislative, regulatory and economic developments, including regulatory implementation of the Inflation Reduction Act, timely and attractive permitting for carbon capture and storage by applicable federal and state regulators, and other regulatory actions targeting public companies in the oil and gas industry and changes in local, national, or international laws, regulations, and policies affecting ExxonMobil and Pioneer including with respect to the environment; potential business uncertainty, including the outcome of commercial negotiations and changes to existing business relationships during the pendency of the proposed transaction that could affect ExxonMobil’s and/or Pioneer’s financial performance and operating results; certain restrictions during the pendency of the proposed transaction that may impact Pioneer’s ability to pursue certain business opportunities or strategic transactions or otherwise operate its business; acts of terrorism or outbreak of war, hostilities, civil unrest, attacks against ExxonMobil or Pioneer, and other political or security disturbances; dilution caused by ExxonMobil’s issuance of additional shares of its common stock in connection with the proposed transaction; the possibility that the transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events; changes in policy and consumer support for emission-reduction products and technology; the impacts of pandemics or other public health crises, including the effects of government responses on people and economies; global or regional changes in the supply and demand for oil, natural gas, petrochemicals, and feedstocks and other market or economic conditions that impact demand, prices and differentials, including reservoir performance; changes in technical or operating conditions, including unforeseen technical difficulties; those risks described in Item 1A of ExxonMobil’s Annual Report on Form 10-K, filed with the SEC on February 22, 2023, and subsequent reports on Forms 10-Q and 8-K, as well as under the heading “Factors Affecting Future Results” under the tab “Resources” on the Investors page of ExxonMobil’s website at www.exxonmobil.com (information included on or accessible through ExxonMobil’s website is not incorporated by reference into this communication); those risks described in Item 1A of

Pioneer’s Annual Report on Form 10-K, filed with the SEC on February 23, 2023, and subsequent reports on Forms 10-Q and 8-K; and those risks that will be described in the registration statement on Form S-4 and accompanying prospectus available from the sources indicated above. References to resources or other quantities of oil or natural gas may include amounts that ExxonMobil or Pioneer believe will ultimately be produced, but that are not yet classified as “proved reserves” under SEC definitions.

These risks, as well as other risks associated with the proposed transaction, will be more fully discussed in the proxy statement/prospectus that will be included in the registration statement on Form S-4 that will be filed with the SEC in connection with the proposed transaction. While the list of factors presented here is, and the list of factors to be presented in the registration statement on Form S-4 will be, considered representative, no such list should be considered to be a complete statement of all potential risks and uncertainties. Unlisted factors may present significant additional obstacles to the realization of forward-looking statements. We caution you not to place undue reliance on any of these forward-looking statements as they are not guarantees of future performance or outcomes and that actual performance and outcomes, including, without limitation, our actual results of operations, financial condition and liquidity, and the development of new markets or market segments in which we operate, may differ materially from those made in or suggested by the forward-looking statements contained in this communication. Neither ExxonMobil nor Pioneer assumes any obligation to publicly provide revisions or updates to any forward-looking statements, whether as a result of new information, future developments or otherwise, should circumstances change, except as otherwise required by securities and other applicable laws. Neither future distribution of this communication nor the continued availability of this communication in archive form on ExxonMobil’s or Pioneer’s website should be deemed to constitute an update or re-affirmation of these statements as of any future date.