Note 8 - Net Loss Per Share Attributable to Common Stockholders

3 Months Ended

Mar. 31, 2018

Notes to Financial Statements

Earnings Per Share [Text Block]

8. Net Loss per Share Attributable to Common Stockholders

As described in Note

2,

Summary of Significant Accounting Policies, the Company computes basic and diluted loss per share using a methodology that gives effect to the impact of outstanding participating securities (the “two-class method”). As the

three

months ended

March 31, 2018

and

2017

resulted in net losses, there is

no

income allocation required under the

two

-class method or dilution attributed to weighted-average shares outstanding in the calculation of diluted loss per share.

The following Common Stock equivalents, presented on an as converted basis, were excluded from the calculation of net loss per share for the periods presented, due to their anti-dilutive effect:

	Three Months Ended March 31,
	2018		2017
Outstanding stock options		4,380,937		2,751,595
Outstanding ESPP shares		55,716		91,740
Convertible preferred stock		22,112,775		-
		26,549,428		2,843,335