2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The components of basic and diluted net loss per share were as follows (in thousands, except loss per share data):

		Year Ended December 31,
		2021		2020		2019
Numerator:
Net loss available for common shareholders	$	(43,200)	$	(13,634)	$	(26,483)
Denominator:
Weighted-average common shares outstanding		160,662		139,829		111,297
Net loss per share - basic and diluted	$	(0.27)	$	(0.10)	$	(0.24)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

During each of the years ended December 31, 2021, 2020 and 2019, we excluded the following securities from net loss per share as the effect of including them would have been anti-dilutive. The shares shown represent the number of shares of common stock which would be issued upon conversion in the respective years shown below (in thousands):

	Year Ended December 31,
	2021	2020	2019
Options outstanding	1,533	3,281	5,104
Nonvested restricted stock units	2,625	1,982	1,215
	4,158	5,263	6,319

Expensed Share-based Payments

The following table summarizes the amount of share-based compensation expense by line item on the Statement of Operations (in thousands):

		Year Ended December 31,
		2021		2020		2019
Cost of product revenue	$	-	$	-	$	26
Research and development expense		6,125		699		379
Sales, marketing, general and administrative expense		9,159		598		1,209
	$	15,284	$	1,297	$	1,614