Common Contracts

Filed Pursuant to Rule 424(b)(3) Registration No. 333-234080 MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT Dear Stockholder of SemGroup Corporation:

Agreement and Plan of Merger • May 5th, 2020 • Delaware

• Contract Type
  Agreement and Plan of Merger
• Filed
  May 5th, 2020
• Jurisdiction
  Delaware

On September 15, 2019, SemGroup Corporation (“SemGroup”) entered into an Agreement and Plan of Merger (the “merger agreement”) with Energy Transfer LP (“Energy Transfer”) and Nautilus Merger Sub LLC, a wholly owned subsidiary of Energy Transfer (“Merger Sub”), pursuant to which Merger Sub will merge with and into SemGroup (the “merger”), with SemGroup surviving the merger as a direct wholly owned subsidiary of Energy Transfer.