Common Stock and Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of basic and diluted net loss per share

Basic and diluted net loss per common share were as follows (in thousands, except per share amounts):


	Year Ended December 31,
	2021		2020
Net loss	$	(37,144)	$	(22,710)
Dividends on preferred stock - declared and undeclared	(8,954)		(1,987)
Net loss attributable to common stockholders	$	(46,098)	$	(24,697)

Weighted-average shares of common stock outstanding	18,656		17,112
Net loss per common share - basic and diluted	$	(2.47)	$	(1.44)

Schedule of shares excluded from calculation of diluted earnings per share

The following common equivalent shares issuable upon the exercise of stock options and warrants have been excluded from the calculation of diluted earnings per common share as their effect was anti-dilutive:


	December 31,
	2021	2020
Warrants to purchase common stock	35,832	1,465,927
Options to purchase	3,618,145	3,616,314
Total shares excluded from net loss per share	3,653,977	5,082,241