STEEL DYNAMICS INC — Director's Dealing 2010

May 25, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: STEEL DYNAMICS INC (STLD)
CIK: 0001022671
Period of Report: 2010-05-21

Reporting Person: TEETS RICHARD P JR (Director, Executive Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-05-21	Common Stock	P	10000	$13.48	Acquired	94000	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-05-21	Employee Stock Option (right to buy)	$13.57	A	4422	Acquired	2015-05-21	Common Stock (4422)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	5916	Indirect
Common stock	5916	Indirect
Common Stock	4976105	Direct

Footnotes

F1: Formula stock option grant, but provided by order of the Compensation Committee and Board, for purposes of this grant date, at 75% of the otherwise applicable dollar amount per grantee, pursuant to the 2006 Equity Incentive Plan and exempt from Section 16(b) pursuant to Rule 16b-3.