Earnings Per Common Share

The following is a reconciliation of the numerators and denominators of the basic and diluted earnings per common share computations for the three months ended March 31, 2018 and 2017 (in millions, except per share amounts):



	Three Months Ended March 31,
	2018		2017
Basic:
Net income attributable to Intercontinental Exchange, Inc.	$	464	$	503
Weighted average common shares outstanding	582		594
Basic earnings per common share	$	0.80	$	0.85
Diluted:
Weighted average common shares outstanding	582		594
Effect of dilutive securities - stock options and restricted shares	4		5
Diluted weighted average common shares outstanding	586		599
Diluted earnings per common share	$	0.79	$	0.84

Basic earnings per common share is calculated using the weighted average common shares outstanding during the period. Common equivalent shares from stock options and restricted stock awards, using the treasury stock method, are included in the diluted per share calculations unless the effect of their inclusion would be antidilutive. During the three months ended March 31, 2018 and 2017, 302,109 and 586,866 outstanding stock options, respectively, were not included in the computation of diluted earnings per common share since the inclusion would have had an antidilutive effect because the outstanding stock option exercise prices were greater than the average market price of the common shares during the relevant periods. Certain figures in the table above may not recalculate due to rounding.