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): March 28, 2018

RSP PERMIAN, INC.

(Exact name of registrant as specified in its charter)

3141 Hood Street, Suite 500 Dallas, Texas 75219

(Address of principal executive offices)

Registrant’s telephone number, including area code: (214) 252-2700

Not Applicable

(Former name or former address, if changed since last report)

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:

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.  ☐

On March 28, 2018, RSP Permian, Inc., a Delaware corporation (“RSP”), and Concho Resources Inc., a Delaware corporation (“Concho”), announced that they had entered into an Agreement and Plan of Merger among RSP, Concho and Green Merger Sub Inc., a Delaware corporation and wholly owned subsidiary of Concho (“Merger Sub”), pursuant to which, subject to the satisfaction or waiver of certain conditions, Merger Sub will merge with and into RSP, with RSP continuing as the surviving entity and an indirect wholly owned subsidiary of Concho. A copy of the joint press release is attached hereto as Exhibit 99.1.

Additionally on March 28, 2018, certain members of management of Concho and RSP participated in an investor conference call. The presentation to investors on that call is attached hereto as Exhibit 99.2.

Solely to the extent required by law, the information set forth in Item 7.01 above is incorporated by reference into this Item 8.01.

No Offer or Solicitation

This communication relates to a proposed business combination transaction (the “Transaction”) between RSP and Concho. This communication is for informational purposes only and does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, in any jurisdiction, pursuant to the Transaction or otherwise, nor shall there be any sale, issuance, exchange or transfer of the securities referred to in this document in any jurisdiction in contravention of applicable law. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

Important Additional Information

In connection with the Transaction, Concho will file with the U.S. Securities and Exchange Commission (“SEC”) a registration statement on Form S-4, that will include a joint proxy statement of RSP and Concho and a prospectus of Concho. The Transaction will be submitted to RSP’s stockholders and Concho’s stockholders for their consideration. RSP and Concho may also file other documents with the SEC regarding the Transaction. The definitive joint proxy statement/prospectus will be sent to the stockholders of Concho and RSP. This document is not a substitute for the registration statement and joint proxy statement/prospectus that will be filed with the SEC or any other documents that Concho or RSP may file with the SEC or send to stockholders of Concho or RSP in connection with the Transaction. INVESTORS AND SECURITY HOLDERS OF RSP AND CONCHO ARE URGED TO READ THE REGISTRATION STATEMENT AND THE JOINT PROXY STATEMENT/PROSPECTUS REGARDING THE TRANSACTION WHEN IT BECOMES AVAILABLE AND ALL 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 BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE TRANSACTION AND RELATED MATTERS.

Investors and security holders will be able to obtain free copies of the registration statement and the joint proxy statement/prospectus (when available) and all other documents filed or that will be filed with the SEC by Concho or RSP through the website maintained by the SEC at http://www.sec.gov. Copies of documents filed with the SEC by RSP will be made available free of charge on RSP’s website at http://www.rspppermian.com, under the heading “SEC Filings,” or by directing a request to Investor Relations, RSP Permian, Inc., 3141 Hood Street, Suite 500, Dallas, Texas 75219, Tel. No. (214) 252-2700. Copies of documents filed with the SEC by Concho will be made available free of charge on Concho’s website at http://www.concho.com/investors or by directing a request to Investor Relations, Concho Resources Inc., One Concho Center, 600 West Illinois Avenue, Midland, Texas 79701, Tel. No. (432) 221-0477.

Participants in Solicitation

Concho, RSP and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies in respect to the Transaction.

Information regarding RSP’s directors and executive officers is contained in the proxy statement for RSP’s 2017 Annual Meeting of Stockholders filed with the SEC on April 28, 2017, and certain of its Current Reports on Form 8-K. You can obtain a free copy of this document at the SEC’s website at http://www.sec.gov or by accessing RSP’s website at http://www.rsppermian.com. Information regarding Concho’s executive officers and directors is contained in the proxy statement for the Concho’s 2017 Annual Meeting of Stockholders filed with the SEC on April 5, 2017 and certain of its Current Reports on Form 8-K. You can obtain a free copy of this document at the SEC’s website at www.sec.gov or by accessing the Concho’s website at http://www.concho.com/investors.

Investors may obtain additional information regarding the interests of those persons and other persons who may be deemed participants in the Transaction by reading the joint proxy statement/prospectus regarding the Transaction when it becomes available. You may obtain free copies of this document as described above.

Forward-Looking Statements and Cautionary Statements

This Current Report on Form 8-K (“Form 8-K”) may contain “forward-looking statements,” including certain plans, expectations, goals, projections and statements about the benefits of the Transaction, RSP’s and Concho’s plans, objectives, expectations and intentions, the expected timing of completion of the transaction, and other statements that are not historical facts. Such statements are subject to numerous assumptions, risks, and uncertainties. Statements that do not describe historical or current facts, including statements about beliefs and expectations, are forward-looking statements. The forward-looking statements are intended to be subject to the safe harbor provided by Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, and the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, included in this communication that address activities, events or developments that Concho or RSP expects, believes or anticipates will or may occur in the future are forward-looking statements. Words such as “estimate,” “project,” “predict,” “believe,” “expect,” “anticipate,” “potential,” “create,” “intend,” “could,” “may,” “foresee,” “plan,” “will,” “guidance,” “look,” “outlook,” “goal,” “future,” “assume,” “forecast,” “build,” “focus,” “work,” “continue” or the negative of such terms or other variations thereof and words and terms of similar substance used in connection with any discussion of future plans, actions, or events identify forward-looking statements. However, the absence of these words does not mean that the statements are not forward-looking. These forward-looking statements include, but are not limited to, statements regarding the Transaction, pro forma descriptions of the combined company and its operations, integration and transition plans, synergies, opportunities and anticipated future performance. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this communication. These include the expected timing and likelihood of completion of the Transaction, including the timing, receipt and terms and conditions of any required governmental and regulatory approvals of the Transaction that could reduce anticipated benefits or cause the parties to abandon the Transaction, the ability to successfully integrate the businesses, the occurrence of any event, change or other circumstances that could give rise to the termination of the merger agreement, the possibility that stockholders of Concho may not approve the issuance of new shares of common stock in the Transaction or that stockholders of RSP may not approve the merger agreement, the risk that the parties may not be able to satisfy the conditions to the Transaction in a timely manner or at all, risks related to disruption of management time from ongoing business operations due to the Transaction, the risk that any announcements relating to the Transaction could have adverse effects on the market price of Concho’s common stock or RSP’s common stock, the risk that the Transaction and its announcement could have an adverse effect on the ability of Concho and RSP to retain customers and retain and hire key personnel and maintain relationships with their suppliers and customers and on their operating results and businesses generally, the risk the pending Transaction could distract management of both entities and they will incur substantial costs, the risk that problems may arise in successfully integrating the businesses of the companies, which may result in the combined company not operating as effectively and efficiently as expected, the risk that the combined company may be unable to achieve synergies or it may take longer than expected to achieve those synergies and other important factors that could cause actual results to differ materially from those projected. All such factors are difficult to predict and are beyond Concho’s and RSP’s control, including those detailed in Concho’s annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K that are available on its website at http://www.concho.com and on the SEC’s website at http://www.sec.gov, and those detailed in RSP’s annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K that are available on RSP’s website at http://www.rsppermian.com and on the SEC’s website at http://www.sec.gov.

Each of the forward-looking statements of Concho or RSP are based on assumptions that RSP or Concho, as applicable, believes to be reasonable but that may not prove to be accurate. Any forward-looking statement speaks only as of the date on which such statement is made, and RSP nor Concho undertakes any obligation to correct or update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by applicable law. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof.

(d) Exhibits.

SIGNATURES

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