Stock Based Compensation (Tables)
|
9 Months Ended |
Sep. 30, 2019 |
|---|
| Share-based Payment Arrangement, Noncash Expense [Abstract] |
|
| Schedule of stock-based compensation expense |
The amount of stock-based compensation expense recognized for the three and nine months ended September 30, 2019 and 2018 was as follows:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Three Months Ended September 30, |
|
Nine Months Ended September 30, |
|
|
2019 |
|
2018 |
|
2019 |
|
2018 |
Research and development |
|
$ |
176,261 |
|
|
$ |
32,202 |
|
|
$ |
354,347 |
|
|
$ |
64,077 |
|
General and administrative |
|
473,905 |
|
|
843,122 |
|
|
1,139,241 |
|
|
1,599,703 |
|
Sales and marketing |
|
168,627 |
|
|
69,809 |
|
|
448,608 |
|
|
132,607 |
|
Total stock-based compensation |
|
$ |
818,793 |
|
|
$ |
945,133 |
|
|
$ |
1,942,196 |
|
|
$ |
1,796,387 |
|
|
| Summary of option activity |
A summary of option activity for the nine months ended September 30, 2019 is as follows:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Options Outstanding |
|
|
Number of shares |
|
Weighted average exercise price per share |
|
Weighted average grant date fair value of options |
|
Weighted average remaining contractual term (in years) |
Balance at December 31, 2018 |
|
3,746,597 |
|
|
$ |
4.16 |
|
|
|
|
|
7.8 |
Granted |
|
2,618,264 |
|
|
$ |
5.71 |
|
|
$ |
8,076,475 |
|
|
|
Exercised |
|
(75,178 |
) |
|
$ |
3.44 |
|
|
|
|
|
Forfeited |
|
(902,767 |
) |
|
$ |
5.16 |
|
|
$ |
2,640,665 |
|
|
|
Expired |
|
(389,792 |
) |
|
$ |
5.03 |
|
|
$ |
992,343 |
|
|
|
Balance at September 30, 2019 |
|
4,997,124 |
|
|
$ |
4.74 |
|
|
|
|
|
8.2 |
Exercisable at September 30, 2019 |
|
2,155,081 |
|
|
$ |
4.36 |
|
|
|
|
|
6.9 |
The Company has granted awards that contain market-based vesting conditions. The following table summarizes the Company's market-based option activity for the nine months ended September 30, 2019:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Options Outstanding |
|
|
Number of shares |
|
Weighted average exercise price per share |
|
Weighted average remaining contractual term (in years) |
|
Aggregate intrinsic value (1) |
Balance at December 31, 2018 |
|
500,000 |
|
|
$ |
4.24 |
|
|
9.2 |
|
|
Granted |
|
300,000 |
|
|
$ |
4.98 |
|
|
|
|
|
Exercised |
|
— |
|
|
|
|
|
|
|
Forfeited |
|
(500,000 |
) |
|
$ |
4.24 |
|
|
|
|
|
Balance at September 30, 2019 |
|
300,000 |
|
|
$ |
4.98 |
|
|
9.65 |
|
$ |
— |
|
Exercisable at September 30, 2019 |
|
— |
|
|
|
|
|
|
|
(1) The aggregate intrinsic value in the above table represents the total pre-tax amount that a participant would receive if the option had been exercised on the last day of the respective fiscal period. Options with a market value less than its exercise value are not included in the intrinsic value amount.
|
| Schedule of fair value assumptions for options |
The following table shows the assumptions used to compute stock-based compensation expense for stock options granted to employees and members of the board of directors under the Black-Scholes valuation model and the assumptions used to compute stock-based compensation expense for market-based stock options grants under a Monte Carlo simulation for the nine months ended September 30, 2019:
|
|
|
|
Service-based options |
|
|
Expected dividend yield |
|
—% |
Expected volatility |
|
55% |
Expected life (in years) |
|
5.0 - 6.25 |
Risk-free interest rate |
|
1.47 - 2.59% |
|
|
Market-based options |
|
|
Expected dividend yield |
|
—% |
Expected volatility |
|
60% |
Expected life (in years) |
|
10 |
Risk-free interest rate |
|
2.32% |
|
| Nonvested Restricted Stock Shares Activity |
The following table summarizes the Company's RSU activity for nine months ended September 30, 2019:
|
|
|
|
|
|
|
|
|
|
|
RSUs Outstanding |
|
|
Number of shares |
|
Weighted average grant date fair value |
Unvested RSUs at December 31, 2018 |
|
445,000 |
|
|
$ |
4.27 |
|
Granted |
|
295,000 |
|
|
$ |
4.98 |
|
Vested |
|
(172,500 |
) |
|
$ |
4.52 |
|
Forfeited |
|
(300,000 |
) |
|
$ |
4.24 |
|
Unvested RSUs at September 30, 2019 |
|
267,500 |
|
|
|
|