UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.    )

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Filed by a Party other than the Registrant ¨
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¨	Preliminary Proxy Statement
¨	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
¨	Definitive Proxy Statement
x	Definitive Additional Materials
¨	Soliciting Material Pursuant to §240.14a-12

Steel Dynamics, Inc.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
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 . · ·.· 7575 WEST JEFFER SON BLVD. FORT WAYNE, IN 46804 el In . Your Vote Counts ! STEEL DYNAMICS, INC. 2021 Annual Meeting Vote by May 18, 2021 11:59 PM ET You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholder meeting to be held on May 19, 2021. Get informed before you vote View the Notice & Proxy Statement, Form 10-K, Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to May 05, 2021. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Smartphone users Point your camera here and vote without entering a I n u m ber Vote in Person at the Meeting* May 19, 2021 9:00 AM EDT Courtyard by Marriott 1150 South Harrison Street Fort Wayne, Indiana 46802 *Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares.

Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. Voting Items Board Recommends NOTE: Unless otherwise directed, this proxy will be voted " FOR " the nominees listed in Proposal 1, and " For " Proposals 2 and 3. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Sign up for E-delivery".