XML 38 R28.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock Option Plan (Tables)
9 Months Ended
Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Schedule of Activity Under Stock Option Plan
The following table summarizes activity under the Plan for the nine months ended September 30, 2018:
 
 
Options Outstanding
 
 
 
 
 
 
Shares
Available
for
Grant
 
Number of
Shares
 
Weighted-
Average
Exercise
Price
 
Weighted-
Average
Remaining
Contractual
Life
 
Aggregate
Intrinsic
Value
 
 
 
 
 
 
 
 
(in years)
 
(in thousands)
 
 
 
 
 
 
 
 
 
 
 
Balances at December 31, 2017
 
29,654

 
3,001,929

 
$
4.15

 
 
 
$
3,585

Options granted
 
(73,783
)
 
73,783

 
5.51

 
 
 
 
Options exercised
 

 
(309,767
)
 
4.11

 
 
 
960

Options cancelled
 
54,278

 
(54,278
)
 
4.77

 
 
 
 
Balances at September 30, 2018
 
10,149

 
2,711,667

 
$
4.12

 
6.8
 
$
23,957

 
 
 
 
 
 
 
 
 
 
 
Options vested and exercisable - September 30, 2018
 
 
 
1,639,606

 
$
3.65

 
6.0
 
$
15,271

 
 
 
 
 
 
 
 
 
 
 
Options vested and expected to vest - September 30, 2018
 
 
 
2,489,664

 
$
4.01

 
6.7
 
$
22,285

Schedule of Stock-Based Compensation
The following table sets forth stock-based compensation expense related to options granted for the periods presented (in thousands):
 
 
Three Months Ended
September 30,
 
Nine Months Ended
September 30,
 
 
2018
 
2017
 
2018
 
2017
 
 
 
 
 
 
 
Cost of goods sold
 
$
5

 
$
5

 
$
17

 
$
18

Research and development
 
30

 
33

 
101

 
98

Sales and marketing
 
110

 
107

 
350

 
313

General and administrative
 
183

 
198

 
613

 
609

 
 
$
328

 
$
343

 
$
1,081

 
$
1,038

Schedule of Valuation Assumptions Related to Stock Option Awards
The grant date fair value of the stock option awards granted to employees was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:
 
Three months ended
 
Nine months ended
 
September 30,
 
September 30,
 
2018
 
2017
 
2018
 
2017
 
 
 
 
Expected term
6.04
 
6.03
 
5.98
 
5.05
Expected volatility
41%-44%
 
42%-46%
 
41%-46%
 
41%-55%
Risk-free interest rate
2.74%-2.80%
 
1.73%-2.15%
 
2.35%-2.93%
 
1.73%-2.75%
Dividend yield
—%
 
—%
 
—%
 
—%