On January 8, 2020, Cleveland-Cliffs Inc. (Cliffs) filed a registration statement on Form S-4
(File No. 333-235855) (as amended, the Form S-4) with the Securities and Exchange Commission (the SEC) in connection with the
proposed acquisition of AK Steel Holding Corporation (the Company or AK Steel) by Cliffs pursuant to an Agreement and Plan of Merger, dated as of December 2, 2019 (as the same may be amended from time to
time, the Merger Agreement), by and among Cliffs, the Company and Pepper Merger Sub Inc., a direct, wholly owned subsidiary of Cliffs (Merger Sub). On February 4, 2020, the Company filed with the SEC its
definitive joint proxy statement on Schedule 14A relating to the special meeting of stockholders of the Company scheduled to be held on March 10, 2020 (the Definitive Proxy Statement) to, among other things, vote on a
proposal to adopt the Merger Agreement.
Since the initial filing of the Form S-4, seven actions (collectively,
the AK Steel Federal Stockholder Actions), including one putative class action lawsuit, have been filed in federal courts in Delaware, Michigan and New York by purported AK Steel stockholders in connection with the transactions
contemplated by the Merger Agreement: Stein v. AK Steel Holding Corp., et al., Case No. 1:20-cv-00054 (D. Del., filed January 14, 2020); Spuhler v. AK
Steel Holding Corp., et al., Case No. 1:20-cv-00444 (S.D.N.Y., filed January 16, 2020); Franchi v. AK Steel Holding Corp., et al., Case No. 1:20-cv-00078 (D. Del., filed January 17, 2020) (the Franchi Action); Raul v. AK Steel Holding Corp., et al., No.
1:20-cv-00611 (S.D.N.Y., filed January 23, 2020); Ruiz v. AK Steel Holding Corp., et al., Case No. 1:20-cv-00620 (E.D.N.Y., filed February 4, 2020); Rubin v. AK Steel Holding Corp., et al., Case No. 2:20-cv-10379
(E.D. Mich., filed February 12, 2020); and Cornish v. AK Steel Holding Corp., et al., Case No. 2:20-cv-10457 (E.D. Mich., filed February 21, 2020). An
eighth action, Pate v. AK Steel Holding Corp., et al., Case No. CV 2020 01 0196 (Ohio Common Pleas, Butler County, filed January 28, 2020) (the Pate Action and together with the AK Steel Federal Stockholder Actions,
the AK Steel Stockholder Actions) has been filed by a purported AK Steel stockholder as a putative class action in state court in Ohio. Each of the AK Steel Stockholder Actions names AK Steel and its directors as defendants, and
the Franchi Action and Pate Action name Cliffs and Merger Sub as additional defendants. A ninth action, Nessim v. Cleveland-Cliffs Inc., et al., Case No. 1:20-cv-00850
(S.D.N.Y., filed January 31, 2020) (the Nessim Action and, together with the AK Steel Federal Stockholder Actions, the Federal Stockholder Actions), has been filed in federal court in New York against
Cliffs and its directors by a purported shareholder of Cliffs. Each of the Federal Stockholder Actions alleges, among other things, that the Form S-4 is false and misleading and/or omits material information
concerning the transactions contemplated by the Merger Agreement in violation of Sections 14(a) and 20(a) of the Securities Exchange Act of 1934, as amended (the Exchange Act), and Rule
14a-9 promulgated under the Exchange Act. The Pate Action alleges breach of fiduciary duty claims against the Companys directors and aiding and abetting claims against the Company, Cliffs and Merger Sub
in connection with the transactions contemplated by the Merger Agreement, including that the Form S-4 is false and misleading and/or omits material information concerning the transactions contemplated by the
Merger Agreement. The plaintiffs in the Federal Stockholder Actions and the Pate Action (collectively, the Stockholder Actions), among other things, seek to enjoin the transactions contemplated by the Merger Agreement and an award
of attorneys fees and expenses.
SUPPLEMENT TO DEFINITIVE PROXY STATEMENT
This supplemental information should be read in conjunction with the Definitive Proxy Statement, which should be read in its entirety. Page references in
the below disclosures are to pages in the Definitive Proxy Statement, and defined terms used but not defined herein have the meanings set forth in the Definitive Proxy Statement. To the extent the following information differs from or conflicts with
the information contained in the Definitive Proxy Statement, the information set forth below shall be deemed to supersede the respective information in the Definitive Proxy Statement. The Company and Cliffs deny the allegations in the complaints
related to the Stockholder Actions and deny any alleged violations of law or any legal or equitable duty. Without admitting in any way that the disclosures below are material or otherwise required by law, the Company and Cliffs make the following
amended and supplemental disclosures solely for the purpose of mooting the allegations in the complaints related to the Stockholder Actions.
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