Net Loss Per Share

6 Months Ended

Jun. 30, 2019

8. Net Loss Per Share

Net income (loss) per share was calculated as follows:

	Three Months Ended June 30,					Six Months Ended June 30,
(in thousands, except per share data)	2019		2018			2019			2018
Net income (loss) - basic and diluted	$	51,338	$	(5,913	)	$	(50,777	)	$	(47,731	)
Weighted-average common shares outstanding:
Basic		91,389		90,100			91,226			89,814
Effect of dilutive securities:
Employee stock purchase program		41		—			—			—
Stock options		2,551		—			—			—
Restricted stock		285		—			—			—
2024 Notes		513		—			—			—
Diluted		94,779		90,100			91,226			89,814
Net income (loss) per share:
Basic	$	0.56	$	(0.07	)	$	(0.56	)	$	(0.53	)
Diluted	$	0.54	$	(0.07	)	$	(0.56	)	$	(0.53	)

In loss periods, basic net loss per share and diluted net loss per share are identical because the otherwise dilutive potential common shares become anti-dilutive and are therefore excluded.

Convertible debt instruments that may be settled entirely or partly in cash (such as the 2024 Notes) may, in certain circumstances where the borrower has the ability and intent to settle in cash, be accounted for under the treasury stock method. We issued the 2024 Notes with a combination settlement feature, which we have the ability and intent to use upon conversion of the 2024 Notes, to settle the principal amount of debt for cash and the excess of the principal portion in shares of our common stock. As a result, of the approximately 6.8 million shares underlying the 2024 Notes, only the shares required to settle the excess of the principal portion are considered under the treasury stock method.

Shares which have been excluded from diluted per share amounts because their effect would have been anti-dilutive consisted of the following:

Three Months Ended

June 30,

Six Months Ended

June 30,

(in thousands)

2019

2018

2019

2018

Stock options, restricted stock and convertible senior notes

2,349

8,422

8,533

8,289