Net Income (Loss) Per Common Share

12 Months Ended

Dec. 31, 2018

12. Net Income (Loss) per Common Share

Basic net income (loss) per share excludes dilution for potentially dilutive securities and is computed by dividing net income (loss) by the weighted average number of common shares outstanding during the period. Diluted net income (loss) per share reflects the potential dilution under the treasury method that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. For periods where the Company has presented a net loss, potentially dilutive securities are excluded from the computation of diluted net loss per share as they would be antidilutive.

The following tables summarize the components of the basic and diluted net income (loss) per common share computations (in thousands, except per share amounts):

	Year Ended December 31,
	2018			2017			2016
Basic EPS:
Net (loss) income (numerator)	$	(86,975	)	$	(117,333	)	$	125,664
Weighted average common shares (denominator)		144,136			104,245			92,053
Net (loss) income per share	$	(0.60	)	$	(1.13	)	$	1.37
Diluted EPS:
Net (loss) income (numerator)	$	(86,975	)	$	(117,333	)	$	125,664
Weighted average common shares		144,136			104,245			92,053
Effect of dilutive securities - common shares issuable		—			—			32
Adjusted weighted average common shares (denominator)		144,136			104,245			92,085
Net (loss) income per share	$	(0.60	)	$	(1.13	)	$	1.36

Common shares issuable represents incremental shares of common stock which consist of stock options, restricted stock units, warrants, and shares that could be issued upon conversion of the senior convertible notes and the Mann Group Loan Arrangement.

Potentially dilutive securities outstanding that are considered antidilutive, in the periods noted below, are summarized as follows (in shares):

	December 31,
	2018		2017		2016
Vesting of restricted stock units		691,266		1,135,216		702,867
Employee stock purchase plan		307,395		136,660		43,672
Exercise of common stock options		10,976,118		7,089,440		5,530,256
Conversion of convertible notes into common stock		3,629,627		6,875,272		814,561
Conversion of convertible notes payable to related party into common stock		21,909,541		—		—
Exercise of common stock warrants		31,851		31,856		9,740,597
Exercise of warrants associated with public offering		26,666,667		—		—
Exercise of warrants associated with direct placement		14,000,000		—		—
		78,212,465		15,268,444		16,831,953