FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Financial Liabilities

The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands): 

	At March 31, 2021
	Level 1		Level 2		Level 3		Total
2017 Placement Warrants Liability	$	—	$	—	$	4,072	$	4,072
2016 Placement Warrants Liability		—		—		1,412		1,412
Total	$	—	$	—	$	5,484	$	5,484

	At December 31, 2020
	Level 1		Level 2		Level 3		Total
2017 Placement Warrants Liability	$	—	$	—	$	3,675	$	3,675
2016 Placement Warrants Liability		—		—		1,189		1,189
Total	$	—	$	—	$	4,864	$	4,864

Summary of Changes in Fair Value of Level 3 Financial Liabilities

The following table sets forth a summary of the changes in fair value of the Company’s Level 3 financial liabilities (in thousands):

	Three Months Ended March 31,
	2021			2020
Fair value, beginning of period	$	4,864		$	5,373
Change in fair value of Level 3 financial liabilities		947			(2,869	)
Fair value of 2016 Placement Warrants at exercise		(2	)		—
Fair value of 2017 Placement Warrants at exercise		(325	)		—
Fair value, end of period	$	5,484		$	2,504