E. Earnings Per Share – Basic earnings per share (EPS) amounts are computed by dividing earnings by the average number of common shares outstanding. Diluted EPS amounts assume the issuance of common stock for all potentially dilutive share equivalents outstanding.

The information used to compute basic and diluted EPS attributable to Alcoa Corporation common shareholders was as follows (shares in millions):

	Third quarter ended September 30,						Nine months ended September 30,
	2019			2018			2019			2018
Net (loss) income attributable to Alcoa Corporation	$	(221	)	$	(6	)	$	(822	)	$	199
Average shares outstanding – basic		186			186			185			186
Effect of dilutive securities:
Stock options		—			—			—			1
Stock units		—			—			—			2
Average shares outstanding – diluted		186			186			185			189

In the third quarter and nine-month period of 2019, basic average shares outstanding and diluted average shares outstanding were the same because the effect of potential shares of common stock was anti-dilutive since Alcoa Corporation generated a net loss. As a result, five million stock units and stock options combined were not included in the computation of diluted EPS for both the third quarter and nine-month period of 2019. Had Alcoa Corporation generated net income in the third quarter or nine-month period of 2019, one million common share equivalents related to stock units and stock options combined would have been included in diluted average shares outstanding for the respective periods.

In the third quarter of 2018, basic average shares outstanding and diluted average shares outstanding were the same because the effect of potential shares of common stock was anti-dilutive since Alcoa Corporation generated a net loss. As a result, four million stock awards and stock options combined were not included in the computation of diluted EPS. Had Alcoa Corporation generated net income in the third quarter of 2018, two million potential shares of common stock related to stock awards and stock options combined would have been included in diluted average shares outstanding.