GRAINGER W W INC | 2013 | FY | 3

The Company had no shares of preferred stock outstanding as of December 31, 2013 and 2012. The activity related to outstanding common stock and common stock held in treasury was as follows:
 
2013
 
2012
 
Outstanding Common Stock
Treasury Stock
 
Outstanding Common Stock
Treasury Stock
Balance at beginning of period
69,478,495

40,180,724

 
69,962,852

39,696,367

Exercise of stock options, net of 5,134, and 5,310 shares swapped in stock-for-stock exchange, respectively
800,101

(800,101
)
 
966,705

(966,705
)
Settlement of restricted stock units, net of 135,341 and 121,353 shares retained, respectively
232,483

(232,483
)
 
225,997

(225,997
)
Settlement of performance share units, net of 39,874 and 23,590 shares retained, respectively
61,860

(61,860
)
 
44,051

(44,051
)
Purchase of treasury shares
(1,719,001
)
1,719,001

 
(1,721,110
)
1,721,110

Balance at end of period
68,853,938

40,805,281

 
69,478,495

40,180,724

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