Per Share Information

9 Months Ended

Sep. 30, 2020

The following table sets forth the computation of basic and diluted income (loss) per common share:


	Three months ended				Nine months ended
(In millions, except per share amounts)	September 30,				September 30,
	2020		2019		2020		2019
Numerator:
Numerator for basic income (loss) per common share –
Net income (loss) attributable to ATI	$	(50.1)	$	111.0	$	(451.6)	$	201.1
Effect of dilutive securities:
4.75% Convertible Senior Notes due 2022	—		3.2		—		9.7
3.5% Convertible Senior Notes due 2025	—		—		—		—
Numerator for diluted income (loss) per common share –
Net income (loss) attributable to ATI after assumed conversions	$	(50.1)	$	114.2	$	(451.6)	$	210.8
Denominator:
Denominator for basic net income (loss) per common share – weighted average shares	126.6		125.9		126.5		125.7
Effect of dilutive securities:
Share-based compensation	—		0.9		—		0.8
4.75% Convertible Senior Notes due 2022	—		19.9		—		19.9
3.5% Convertible Senior Notes due 2025	—		—		—		—
Denominator for diluted net income (loss) per common share – adjusted weighted average shares and assumed conversions	126.6		146.7		126.5		146.4
Basic net income (loss) attributable to ATI per common share	$	(0.40)	$	0.88	$	(3.57)	$	1.60
Diluted net income (loss) attributable to ATI per common share	$	(0.40)	$	0.78	$	(3.57)	$	1.44

Common stock that would be issuable upon the assumed conversion of the 2022 Convertible Notes and the 2025 Convertible Notes and other option equivalents and contingently issuable shares are excluded from the computation of contingently issuable shares, and therefore, from the denominator for diluted earnings per share, if the effect of inclusion is anti-dilutive. There were 25.0 million and 21.9 million anti-dilutive shares for the three and nine month periods ended September 30, 2020, respectively. There were no anti-dilutive shares for the three and nine months periods ended September 30, 2019.