Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income attributable to Amkor common stockholders by the weighted-average number of common shares outstanding during the period. The weighted-average number of common shares outstanding is reduced for treasury stock.

Diluted EPS is computed based on the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period. Dilutive potential common shares include outstanding stock options and unvested restricted shares.

The following table summarizes the computation of basic and diluted EPS:



	For the Three Months Ended March 31,
	2018		2017
	(In thousands, except per share data)
Net income (loss) attributable to Amkor common stockholders	$	9,544	$	(14,786	)

Weighted-average number of common shares outstanding — basic	239,214		238,685
Effect of dilutive securities:
Stock options and restricted share awards	602		—
Weighted-average number of common shares outstanding — diluted	239,816		238,685
Net income (loss) attributable to Amkor per common share:
Basic	$	0.04	$	(0.06	)
Diluted	0.04		(0.06		)

The following table summarizes the potential shares of common stock that were excluded from diluted EPS, because the effect of including these potential shares was anti-dilutive:



	For the Three Months Ended March 31,
	2018	2017
	(In thousands)
Stock options and restricted share awards	3,369	5,449