9. EARNINGS (LOSS) PER SHARE

Basic earnings (loss) per share are computed based on the weighted average number of shares of common stock outstanding during the period. Common stock equivalents are included in the calculation of diluted earnings per share only when the effect of their inclusion would be dilutive.

The following table sets forth the calculation of basic and diluted earnings (loss) per share and reconciles basic weighted average shares to diluted weighted average shares of common stock outstanding for the periods indicated (in thousands):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Net income (loss)	$	9,019	$	52,406	$	89,937	$	(66,489	)
Effect of dilutive securities:
2013 8.00% Notes	28		388		66		—
Loan Agreement with Thermo	4,387		2,520		10,256		—
Income (loss) to common stockholders plus assumed conversions	$	13,434	$	55,314	$	100,259	$	(66,489	)
Weighted average common shares outstanding:
Basic shares outstanding	1,264,516		1,169,993		1,263,416		1,137,854
Incremental shares from assumed exercises, conversions and other issuance of:
Stock options, restricted stock, restricted stock units and ESPP	2,370		7,364		5,661		—
2013 8.00% Notes	1,867		2,157		2,087		—
Loan Agreement with Thermo	159,047		166,391		177,756		—
Diluted shares outstanding	1,427,800		1,345,905		1,448,920		1,137,854
Net income (loss) per share:
Basic	$	0.01	$	0.04	$	0.07	$	(0.06	)
Diluted	0.01		0.04		0.07		(0.06		)

For the nine months ended September 30, 2017, 171.5 million shares of potential common stock were excluded from diluted shares outstanding because the effects of assuming issuance of these potentially dilutive securities would be anti-dilutive.