EXPLANATORY NOTE
DEREGISTRATION OF SECURITIES
This Post-Effective Amendment No. 1 filed by Jackal Merger Sub A, LLC (as successor in interest to Jagged Peak Energy Inc., a Delaware
corporation (Jagged Peak)), a Delaware limited liability company (the Company), is being filed to deregister all shares of common stock, par value $0.01 per share, of the Company (the Common
Stock) remaining unissued under the Registration Statement on Form S-8 (No. 333-215830), filed by Jagged Peak with the U.S. Securities and Exchange Commission
on January 31, 2017, which registered 26,500,000 shares of Common Stock under the Jagged Peak Energy Inc. 2017 Long Term Incentive Plan and 10,236,958 shares of Common Stock under the Jagged Peak Energy Inc. Management Incentive Plan of JPE
Management Holdings LLC (the Registration Statement).
On January 10, 2020, pursuant to the transactions
contemplated by the Agreement and Plan of Merger, dated as of October 14, 2019 (the Merger Agreement), by and among Jagged Peak, Parsley Energy, Inc., a Delaware corporation (Parsley), and Jackal Merger
Sub, Inc., a Delaware corporation and an indirect, wholly-owned subsidiary of Parsley (Merger Sub), Merger Sub was merged with and into Jagged Peak (the Merger), with Jagged Peak surviving the Merger as a
wholly-owned subsidiary of Parsley, and immediately thereafter, as part of the same transaction, Jagged Peak merged with and into the Company, with the Company continuing as the surviving entity.
As a result of the completion of the transactions contemplated by the Merger Agreement, the Company has terminated all offerings of shares of
Common Stock pursuant to the Registration Statement. In accordance with the undertaking made by the Company in the Registration Statement to remove from registration, by means of a post-effective amendment, any of the securities that had been
registered for issuance that remain unsold at the termination of such offering, the Company hereby removes from registration by means of this Post-Effective Amendment No. 1 all shares of Common Stock registered but unsold under the Registration
Statement. The Registration Statement is hereby amended, as appropriate, to reflect the deregistration of such shares of Common Stock and the Company hereby terminates the effectiveness of the Registration Statement.