WARRANT DERIVATIVE LIABILITY (Tables)

9 Months Ended

Sep. 30, 2021

WARRANT DERIVATIVE LIABILITY.

Summary of key assumptions used to determine fair value of warrants

	May 31,			December 31,			September 30,
	2019			2020			2021
Number of shares underlying the warrants		3,000,000			1,645,807			322,807
Fair market value of stock	$	0.95		$	0.48		$	0.41
Exercise price	$	1.30		$	0.3983		$	0.3983
Volatility		133	%		108	%		105	%
Risk-free interest rate		1.93	%		0.36	%		0.98	%
Warrant life (years)		5.00			3.41			2.66

Summary of the changes in the fair value of the warrant derivative liability

	Nine months ended September 30,
	2021		2020
Beginning balance	$	561,368	$	4,620,593
Warrant exercise		(1,523,118)		(82,241)
Change in fair value of warrants derivative liability		1,043,531		(1,375,619)
Ending balance	$	81,781	$	3,162,733