[Form 4] STEEL DYNAMICS INC Insider Trading Activity

Rhea-AI Filing Summary

Steel Dynamics (STLD) director reported an acquisition of common stock tied to dividend-equivalent deferred stock units. On 10/10/2025, the reporting person acquired 155 shares at $0 under the company’s 2023 Equity Incentive Plan via the plan’s dividend reinvestment feature. Following this transaction, the director beneficially owns 50,515 shares, held directly.

The filing notes these DSUs are payable solely in shares of common stock when settled, and the total includes shares from reinvested dividends on underlying DSUs.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Seaman Bradley S

Role Director

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	155	$0.00	--

Holdings After Transaction: Common Stock — 50,515 shares (Direct)

Footnotes (1)

1. Represents the number of shares of common stock underlying additional deferred stock units (DSUs) issued to the reporting person as a dividend equivalent, in connection with this person's retainer as a director under the Company's 2023 Equity Incentive Plan (the "Plan"). This transaction is exempt from both the reporting requirements of Section 16(a), including Rule 16a-11, and the provisions of Section 16(b), by virtue of this dividend reinvestment feature of the Plan and the Company's existing Dividend Reinvestment Plan, as well as being exempt from Section 16(b) independently by virtue of Rule 16b-3(d)(1) and (3). Reportable as directly owned shares of common stock, rather than as a derivative security in Table II, because any and all underlying DSUs are payable, at such time as they are to be settled, solely in shares of common stock. (See Lincoln National Corp. (March 20, 1992) Q.3). Includes shares resulting from reinvestment of dividends on any underlying DSUs included in this total.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Seaman Bradley S

(Last) (First) (Middle)

7575 W. JEFFERSON BLVD

(Street)

FORT WAYNE IN 46804

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
STEEL DYNAMICS INC [ STLD ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
10/10/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	10/10/2025		A		155(1)(2)	A	$0	50,515(3)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents the number of shares of common stock underlying additional deferred stock units (DSUs) issued to the reporting person as a dividend equivalent, in connection with this person's retainer as a director under the Company's 2023 Equity Incentive Plan (the "Plan"). This transaction is exempt from both the reporting requirements of Section 16(a), including Rule 16a-11, and the provisions of Section 16(b), by virtue of this dividend reinvestment feature of the Plan and the Company's existing Dividend Reinvestment Plan, as well as being exempt from Section 16(b) independently by virtue of Rule 16b-3(d)(1) and (3).

2. Reportable as directly owned shares of common stock, rather than as a derivative security in Table II, because any and all underlying DSUs are payable, at such time as they are to be settled, solely in shares of common stock. (See Lincoln National Corp. (March 20, 1992) Q.3).

3. Includes shares resulting from reinvestment of dividends on any underlying DSUs included in this total.

	/s/ Theresa E. Wagler by Power of Attorney	10/14/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did STLD report in this Form 4?

A director acquired 155 shares on 10/10/2025 at $0 via dividend-equivalent DSUs under the 2023 Equity Incentive Plan.

How many Steel Dynamics (STLD) shares does the director own after the transaction?

The director beneficially owns 50,515 shares following the reported transaction.

What is the nature of the award reported by STLD?

Dividend-equivalent deferred stock units (DSUs) issued under the 2023 Equity Incentive Plan, payable solely in common stock when settled.

Was any cash paid for the acquired shares?

No. The acquisition price was $0, reflecting a dividend-equivalent issuance under the plan.

Is the ownership reported as direct or indirect?

The filing lists the ownership form as Direct (D).

Does the total include reinvested dividends on DSUs?

Yes. The 50,515 shares total includes shares from reinvested dividends on underlying DSUs.