X0306 4 2012-07-27 false 0001336917 Under Armour, Inc. UA 0001241750 MIRCHIN MATTHEW C 1020 HULL STREET BALTIMORE MD 21230 false true false false SVP Global Brand & Sports Mktg Class A Common Stock 2012-07-27 4 S false 15000 54.8879 D 3922 D This transaction was executed in multiple trades at prices ranging from $54.8429 to $54.99. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. All share amounts, and numbers and exercise prices for stock options, have been adjusted to reflect the two-for-one stock split effective July 9, 2012. /s/ John P. Stanton, Attorney in Fact for Matthew C. Mirchin 2012-07-27