Loss Per Share

The Company computes basic loss per share by dividing net loss by the weighted-average common shares outstanding during the period. Diluted loss per share is calculated to give effect to all potentially dilutive common shares that were outstanding during the period. Weighted-average diluted common shares outstanding primarily reflect the additional shares that would be issued upon the assumed exercise of stock options and the assumed vesting of unvested share awards. The treasury stock method has been used to compute diluted loss per share for the three and six months ended June 30, 2019 and 2018.

The Company issued warrants that represent the right to purchase shares of Common Stock, Stock Appreciation Rights (“SARs”) and Restricted Stock Awards (“RSAs”), all of which have been evaluated for their potentially dilutive effect under the treasury stock method. See Note 3. Weichai Transactions herein for additional information on the Weichai Warrants and Note 12. Stock-Based Compensation in the Company’s 2018 Annual Report for additional information on the SARs and the RSAs.

The computations of basic and diluted loss per share are as follows:



(in thousands, except per share basis)	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2019			2018			2019			2018
Numerator:
Net loss	$	(2,998	)	$	(11,805	)	$	(5,584	)	$	(26,009	)

Denominator:
Shares used in computing net loss per share:
Weighted-average basic shares outstanding	21,702			18,594			20,171			18,538
Effect of dilutive securities	—			—			—			—
Weighted-average common shares outstanding – diluted	21,702			18,594			20,171			18,538

Loss per common share:
Loss per share of common stock – basic	$	(0.14	)	$	(0.63	)	$	(0.28	)	$	(1.40	)
Loss per share of common stock – diluted	$	(0.14	)	$	(0.63	)	$	(0.28	)	$	(1.40	)

The aggregate number of shares excluded from the diluted loss per share calculations, because they would have been anti-dilutive, were 1.1 million and 2.7 million shares during the three and six months ended June 30, 2019, respectively and 3.9 million and 4.0 million shares during the three and six months ended June 30, 2018, respectively.