The following table sets forth the computation of basic and diluted earnings per share:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2011		2010		2011		2010
	(in millions, except share and per share amounts)
Numerator:
Net income attributable to NASDAQ OMX	$	110	$	101	$	306	$	258
Accretion of series A convertible preferred stock		—		—		—		(1	)

Net income attributable to common shareholders	$	110	$	101	$	306	$	257

Denominator:
Weighted-average common shares outstanding for basic earnings per share⁽¹⁾		177,097,281		200,115,483		176,616,419		205,558,649

Weighted-average effect of dilutive securities:
Employee equity awards		3,792,679		3,922,926		3,666,109		3,611,480
3.75% convertible notes assumed converted into common stock		34,482		34,482		34,482		34,482

Weighted-average common shares outstanding for diluted earnings per share⁽¹⁾		180,924,442		204,072,891		180,317,010		209,204,611

Basic and diluted earnings per share:
Basic earnings per share	$	0.62	$	0.51	$	1.73	$	1.25

Diluted earnings per share	$	0.61	$	0.50	$	1.70	$	1.23

⁽¹⁾

The decrease in the weighted-average common shares outstanding for basic and diluted earnings per share primarily reflects the weighted-average impact of the share repurchase from Borse Dubai and other purchases related to our share repurchase program completed in 2010. See "Share Repurchase Programs and Share Repurchase from Borse Dubai," of Note 12, "NASDAQ OMX Stockholders' Equity," for further discussion.

Stock options to purchase 10,073,893 shares of common stock, 4,954,820 shares of restricted stock and PSUs, and convertible notes convertible into 34,482 shares of common stock were outstanding at September 30, 2011. For the three months ended September 30, 2011, we included 6,582,278 of the outstanding stock options and 4,871,857 shares of restricted stock and PSUs in the computation of diluted earnings per share, on a weighted-average basis, as their inclusion was dilutive. For the nine months ended September 30, 2011, we included 6,623,764 of the outstanding stock options and 3,012,499 shares of restricted stock and PSUs in the computation of diluted earnings per share, on a weighted-average basis, as their inclusion was dilutive. The remaining stock options and shares of restricted stock and PSUs were antidilutive, and as such, they were properly excluded.

The 3.75% convertible notes are accounted for under the if-converted method, as we previously have settled the convertible notes in shares of our common stock. For the three and nine months ended September 30, 2011 and 2010, all of the shares underlying the outstanding 3.75% convertible notes were included in the computation of diluted earnings per share, as their inclusion was dilutive.

The 2.50% convertible senior notes are accounted for under the treasury stock method as it is our intent and policy to settle the principal amount of the notes in cash. Based on the settlement structure of the 2.50% convertible senior notes, which permits the principal amount to be settled in cash and the conversion premium to be settled in shares of our common stock or cash, we will reflect the impact of the convertible spread portion of the convertible notes in the diluted calculation using the treasury stock method. For the three and nine months ended September 30, 2011 and 2010, the conversion spread of our 2.50% convertible senior notes was out of the money, and as such, they were properly excluded from the computation of diluted earnings per share.

Stock options to purchase 10,467,993 shares of common stock, 4,219,424 shares of restricted stock and PSUs, and convertible notes convertible into 34,482 shares of common stock were outstanding at September 30, 2010. For the three months ended September 30, 2010, we included 5,170,077 of the outstanding stock options and 3,196,888 shares of restricted stock and PSUs in the computation of diluted earnings per share, on a weighted-average basis, as their inclusion was dilutive. For the nine months ended September 30, 2010, we included 5,170,077 of the outstanding stock options and 1,479,215 shares of restricted stock and PSUs in the computation of diluted earnings per share, on a weighted-average basis, as their inclusion was dilutive. The remaining stock options and shares of restricted stock and PSUs were antidilutive, and as such, they were properly excluded.