Stock-based Compensation (Tables)
 3 Months Ended
Apr. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Classification of Stock-based Compensation

The following table presents the classification of stock-based compensation for the periods indicated:

 

 

 

Three Months Ended April 30,

 

 

 

2019

 

 

2018

 

 

 

(in thousands)

 

Stock-based compensation:

 

 

 

 

 

 

 

 

Cost of revenue

 

$

267

 

 

$

315

 

Research and development

 

 

10,204

 

 

 

8,760

 

Selling, general and administrative

 

 

5,989

 

 

 

5,120

 

Total stock-based compensation

 

$

16,460

 

 

$

14,195

 
Weighted-Average Assumptions Used to Estimate Fair Value

The following table sets forth the weighted-average assumptions used to estimate the fair value of stock options and employee stock purchase plan awards for the periods indicated:


 

 

Three Months Ended April 30,

 

 

 

2019

 

 

2018

 

Stock Options:

 

 

 

 

 

 

 

 

Volatility

 

 

52

%

 

 

55

%

Risk-free interest rate

 

 

2.49

%

 

 

2.65

%

Expected term (years)

 

5.88

 

 

5.33

 

Dividend yield

 

 

0

%

 

 

0

%

Employee stock purchase plan awards:

 

 

 

 

 

 

 

 

Volatility

 

 

48

%

 

 

46

%

Risk-free interest rate

 

 

2.52

%

 

 

1.95

%

Expected term (years)

 

0.5

 

 

0.5

 

Dividend yield

 

 

0

%

 

 

0

%
Stock Option Activities

 

The following table summarizes stock option activities for the period indicated:

 

 

Option Outstanding

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Weighted-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Total Intrinsic

 

 

Average

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Weighted-

 

 

Value Of

 

 

Remaining

 

 

Aggregate

 

 

 

 

 

 

 

Weighted-

 

 

Average

 

 

Options

 

 

Contractual

 

 

Intrinsic

 

 

 

 

 

 

 

Average

 

 

Grant-date

 

 

Exercised

 

 

Term

 

 

Value

 

 

 

Shares

 

 

Exercise Price

 

 

Fair Value

 

 

(in thousands)

 

 

(in years)

 

 

(in thousands)

 

Outstanding at January 31, 2019

 

 

1,459,064

 

 

$

28.31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Granted

 

 

18,800

 

 

 

42.13

 

 

$

21.57

 

 

 

 

 

 

 

 

 

 

 

 

 

Exercised

 

 

(101,645

)

 

 

14.95

 

 

 

 

 

 

$

2,767

 

 

 

 

 

 

 

 

 

Forfeited

 

 

(6,448

)

 

 

46.81

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Expired

 

 

(5,358

)

 

 

66.87

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outstanding at April 30, 2019

 

 

1,364,413

 

 

 

29.25

 

 

 

 

 

 

 

 

 

 

4.46

 

 

$

32,360

 

Exercisable at April 30, 2019

 

 

1,170,168

 

 

$

26.28

 

 

 

 

 

 

 

 

 

 

 

3.76

 

 

$

31,285

 
Restricted Stock and Restricted Stock Units Activities

The following table summarizes restricted stock and restricted stock units activities for the period indicated:

 

 

 

 

 

 

 

Weighted-

 

 

 

 

 

 

 

Average

 

 

 

 

 

 

 

Grant-Date

 

 

 

Shares

 

 

Fair Value

 

Unvested at January 31, 2019

 

 

2,395,516

 

 

$

48.49

 

Granted

 

 

407,076

 

 

 

48.11

 

Vested

 

 

(252,076

)

 

 

53.12

 

Forfeited

 

 

(17,322

)

 

 

48.20

 

Unvested at April 30, 2019

 

 

2,533,194

 

 

$

47.97