v3.22.2.2
STOCK PLANS (Tables)
 9 Months Ended
Sep. 30, 2022
Stockholders' Equity Note [Abstract]  
Schedule of recognized stock-based compensation in consolidated statements of operations
The Company recognized stock-based compensation expense in the periods presented as follows (in thousands):
Three Months Ended
September 30,		Nine Months Ended
September 30,
2022202120222021
Cost of goods sold$1,599 $1,512 $4,429 $4,429 
Research and development1,783 1,156 4,761 3,591 
Selling, general and administrative9,300 8,116 26,225 23,336 
        Total$12,682 $10,784 $35,415 $31,356 
Stock-based compensation from:
    Stock options$6,711 $6,458 $20,038 $19,507 
    Restricted stock units5,758 4,126 14,588 11,164 
    Employee stock purchase plan213 200 789 685 
        Total$12,682 $10,784 $35,415 $31,356 
Schedule of the company's stock option activity and restricted stock unit activity
The following tables contain information about the Company’s stock option and restricted stock unit, or RSU, activity for the nine months ended September 30, 2022:
Stock Options Number of Options Weighted Average Exercise Price (Per Share)
 Outstanding at December 31, 2021
6,050,540 $49.32 
     Granted1,034,230 60.16 
     Exercised(667,940)35.18 
     Forfeited(88,766)54.38 
     Expired(24,447)78.76 
 Outstanding at September 30, 2022
6,303,617 52.41 
Restricted Stock Units Number of Units Weighted Average Grant Date Fair Value (Per Share)
Unvested at December 31, 2021
955,277 $52.85 
     Granted598,699 60.43 
     Vested(323,821)50.17 
     Forfeited(68,000)55.04 
Unvested at September 30, 2022
1,162,155 57.38 
Schedule of share-based payment award, stock options, valuation assumptions The fair values of stock options granted were estimated using the Black-Scholes option valuation model with the following weighted average assumptions:
Black-Scholes Weighted Average AssumptionNine Months Ended September 30, 2022
Expected dividend yieldNone
Risk-free interest rate2.84%
Expected volatility45.14%
Expected term of options4.92 years