Equity Securities

9 Months Ended

Sep. 30, 2019

Stockholders Equity Note [Abstract]

Equity Securities

6. Equity Securities

        Increase in Authorized Shares of Common Stock

        On June 4, 2019, our shareholders approved an amendment to our restated articles of incorporation increasing our authorized no par value shares of common stock from 200 million to 300 million shares.

Potentially Dilutive Common Stock Equivalents

As of September 30, 2019 and 2018, we excluded the potentially dilutive securities summarized below, which entitle the holders thereof to potentially acquire shares of common stock, from our calculations of net loss per share and weighted average common shares outstanding, as their effect would have been anti-dilutive (in thousands).

	September 30,
	2019		2018
Common stock warrants issued to underwriter of initial public offering		802		802
Common stock warrants issued in connection with March 2017 rights offering		13,647		13,647
Common stock warrants issued in connection with February 2019 rights offering		47,812		—
Common stock options		8,680		7,581
Restricted stock units		488		47
Employee stock purchase plan		456		191
		71,885		22,268