Stockholders' Equity (Tables)
|
12 Months Ended |
Dec. 31, 2020 |
|---|
| Stockholders’ Equity |
|
| Schedule of common stock warrants by exercise price range |
|
|
|
|
|
|
|
|
|
|
Issuance Date
|
|
Number of Shares
|
|
Exercise Price
|
|
Expiration Date
|
|
3/10/2011
|
|
248
|
|
$
|
33.60
|
|
3/10/2021
|
|
3/23/2016
|
|
42,308
|
|
$
|
70.00
|
|
3/23/2021
|
|
5/7/2018
|
|
403,025
|
|
$
|
11.09
|
|
5/8/2023
|
|
11/26/2018
|
|
313,358
|
|
$
|
11.55
|
|
11/26/2023
|
|
| Schedule of common stock warrants outstanding |
|
|
|
|
|
|
|
Common Stock
|
|
|
|
Warrants
|
|
Outstanding, December 31, 2019
|
|
1,290,103
|
|
Issued
|
|
1,428,571
|
|
Exercised
|
|
(1,489,497)
|
|
Exchanged
|
|
(470,238)
|
|
Outstanding, December 31, 2020
|
|
758,939
|
|
| Schedule of components of stock-based compensation included in net loss |
|
|
|
|
|
|
|
|
|
|
|
For the years ended
|
|
|
|
December 31,
|
|
|
|
2020
|
|
2019
|
|
Employee stock options
|
|
$
|
4,966,596
|
|
$
|
1,349,089
|
|
Non-employee stock options
|
|
|
158,963
|
|
|
351,812
|
|
Employee stock awards
|
|
|
1,072,506
|
|
|
1,243,526
|
|
Non-employee stock awards
|
|
|
179,792
|
|
|
325,521
|
|
|
|
$
|
6,377,857
|
|
$
|
3,269,948
|
|
| Schedule of stock option valuation assumptions |
|
|
|
|
|
|
|
|
|
|
|
2020
|
|
|
2019
|
|
|
Dividend yield
|
|
—
|
%
|
|
—
|
%
|
|
Expected volatility
|
|
83.13-101.68
|
%
|
|
89.59-91.03
|
%
|
|
Risk-free interest rate
|
|
0.26-1.69
|
%
|
|
1.63-2.52
|
%
|
|
Expected lives (years)
|
|
5.0-6.3
|
years
|
|
5.4-6.3
|
years
|
|
| Schedule of stock option activity |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Weighted
|
|
|
|
Weighted
|
|
|
|
|
|
Average
|
|
Aggregate
|
|
Average
|
|
|
|
|
|
Exercise
|
|
Intrinsic
|
|
Remaining
|
|
|
|
Shares
|
|
Price
|
|
Value
|
|
Contractual Life
|
|
Stock options outstanding at December 31, 2018
|
|
66,422
|
|
$
|
81.15
|
|
$
|
—
|
|
|
|
|
Granted
|
|
417,120
|
|
|
7.21
|
|
|
|
|
|
|
|
Exercised
|
|
(285)
|
|
|
7.42
|
|
$
|
—
|
|
|
|
|
Cancelled and expired
|
|
(45,654)
|
|
|
12.33
|
|
|
|
|
|
|
|
Stock options outstanding at December 31, 2019
|
|
437,603
|
|
$
|
17.90
|
|
$
|
44,196
|
|
|
|
|
Granted
|
|
1,167,749
|
|
|
7.90
|
|
|
|
|
|
|
|
Exercised
|
|
(7,140)
|
|
|
3.99
|
|
$
|
9,813
|
|
|
|
|
Forfeited/Expired
|
|
(118,073)
|
|
|
5.80
|
|
|
|
|
|
|
|
Stock options outstanding at December 31, 2020
|
|
1,480,139
|
|
$
|
11.05
|
|
$
|
403,744
|
|
8.6
|
Years
|
|
Stock options exercisable at December 31, 2020
|
|
871,721
|
|
$
|
14.74
|
|
$
|
120,993
|
|
8.1
|
Years
|
|
| Schedule of restricted stock activity |
|
|
|
|
|
|
|
|
|
|
|
|
Weighted
|
|
|
|
|
|
Average
|
|
|
|
Shares
|
|
Fair Value
|
|
Restricted stock at December 31, 2018
|
|
—
|
|
$
|
—
|
|
Granted
|
|
354,165
|
|
|
5.97
|
|
Vested
|
|
(168,272)
|
|
|
5.90
|
|
Cancelled
|
|
(6,388)
|
|
|
7.42
|
|
Restricted stock at December 31, 2019
|
|
179,505
|
|
$
|
5.99
|
|
Granted
|
|
339,999
|
|
|
3.22
|
|
Vested
|
|
(275,115)
|
|
|
4.27
|
|
Cancelled
|
|
(4,461)
|
|
|
7.42
|
|
Restricted stock at December 31, 2020
|
|
239,928
|
|
$
|
4.02
|
|
| Schedule of RSU activity |
|
|
|
|
|
|
|
|
|
|
|
|
Weighted
|
|
|
|
|
|
Average
|
|
|
|
Shares
|
|
Fair Value
|
|
RSUs at December 31, 2018
|
|
8,073
|
|
$
|
33.78
|
|
Vested
|
|
(3,104)
|
|
|
37.37
|
|
Cancelled
|
|
(678)
|
|
|
39.44
|
|
RSUs at December 31, 2019
|
|
4,291
|
|
$
|
30.29
|
|
Vested
|
|
(2,342)
|
|
|
33.15
|
|
Cancelled
|
|
(49)
|
|
|
36.57
|
|
RSUs at December 31, 2020
|
|
1,900
|
|
$
|
26.60
|
|