STEEL DYNAMICS INC — Director's Dealing 2015

May 21, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: STEEL DYNAMICS INC (STLD)
CIK: 0001022671
Period of Report: 2015-05-20

Reporting Person: BUSSE KEITH E (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-05-20	Common Stock	M	5527	$13.57	Acquired	1091465	Direct
2015-05-20	Common Stock	F	3514	$21.34	Disposed	1087951	Direct
2015-05-20	Common Stock	F	751	$21.34	Disposed	1087200	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2015-05-20	Employee Stock Option (right to buy)	$13.57	M	5527	Disposed	2015-05-21	Common Stock (5527)	Direct

Footnotes

F1: Acquisition of stock pursuant to exercise of employee stock option, exempt under Exchange Act Rule 16b-6(b) and Rule 16b-3(d)(1).

F2: Exercise of stock option exempt pursuant to Rule 16b-6(b).

F3: Disposition to Issuer: Shares withheld by Issuer in payment of reporting person's exercise price under stock option in accordance with Exchange Act Rule 16b-3(d)(1) approved in advance by Compensation Committee and exempt from Section 16(b) of Exchange Act in accordance with Exchange Act Rule 16b-3(e).

F4: Payment of withholding tax liability to the issuer, required by mandatory plan provision, by delivering or withholding securities incident to the receipt, exercise or vesting of a security issued in accordance with Rule 16b-3. American Society of Corporate Secretaries, SEC No-Action Letter, Q.2 (December 11, 1996). Romeo & Dye, Sec. 16 Treatise Section 14.06[6], fn 96.