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

10. 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

 

 

During the three months ended April 30, 2019, approximately $1.0 million of stock-based compensation was accrued in the accrued and other current liabilities in the condensed consolidated balance sheets. As of April 30, 2019, total unrecognized compensation cost related to unvested stock options was $4.3 million and is expected to be recognized over a weighted-average period of 2.62 years. Total unrecognized compensation cost related to unvested restricted stock units was $110.3 million and is expected to be recognized over a weighted-average period of 2.57 years. Total unrecognized compensation cost related to unvested restricted stock awards was $0.6 million and is expected to be recognized over a weighted-average period of 0.29 years.

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

%

 

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

 

 

The intrinsic value of options outstanding and exercisable is calculated based on the difference between the fair market value of the Company’s ordinary shares on the reporting date and the exercise price. The closing price of the Company’s ordinary shares on April 30, 2019 was $50.12, as reported by The NASDAQ Global Market. The intrinsic value of exercised options is calculated by the difference between the fair market value of the Company’s ordinary shares on the exercise date and the exercise price.

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

 

 

As of April 30, 2019, the aggregate intrinsic value of unvested restricted stock and restricted stock units was $127.0 million.