NOTE 13. Net Loss Per Share Attributable to Common Stockholders

The following table presents the calculation of basic and diluted net loss per share (in thousands, except share and per share amounts):

	Three Months Ended March 31,
	2018		2017

Net income (loss) attributable to common stockholders – basic calculation	$	1,975	$	(3,506)

Interest charges applicable to convertible promissory notes		295		—

Series B and C preferred dividend		339		—

Series A preferred dividend		(28)		—

Net income (loss) used for net income (loss) per share – diluted calculation		2,581		(3,506)

Shares used to compute net income (loss) per share – basic		3,656,360		135,658

Potential common shares from exercise of options		25,550		—

Shares issuable upon conversion of convertible promissory notes, related party		750,924		—

Shares issuable upon conversion of Series B and C convertible preferred stock and accrued dividends		866,917		—

Shares used to compute net income (loss) per share – diluted		5,299,751		135,658

Net income (loss) per share – basic	$	0.54	$	(25.84)

Net income (loss) per share – diluted	$	0.49	$	(25.84)

No adjustment has been made to the net loss attributable to common stockholders in the three months ended March 31, 2017, as the effect would be anti-dilutive due to the net loss.

The following potentially dilutive securities were excluded from the computation of diluted weighted average shares outstanding because they would have been antidilutive:

	Three Months Ended March 31,
	2018		2017

Options to purchase common stock		529,332		272,287

Warrant to purchase common stock		5,700		—

Warrant to purchase convertible preferred stock		3,613		7,563

Series B and C convertible preferred stock outstanding, including cumulative dividends		—		1,501,566

Series A convertible preferred stock outstanding		—		94,988

Convertible promissory notes, related party (as converted)		—		687,362

Total potentially dilutive securities excluded from denominator of the diluted earnings per share computation		538,645		2,563,766