The Company recognizes compensation costs for stock options awarded to employees based on their grant-date fair value. The value of each stock option is estimated on the date of grant using the Black-Scholes option-pricing model. The weighted-average fair value per share for the stock options granted to employees during the nine months ended September 30, 2019 was $15.72. The weighted-average fair value per share for the stock options granted to employees during the nine months ended September 30, 2018 was $24.54.

For the three months ended September 30, 2019 and 2018, the Company recorded $1,294 and $994, respectively, in “Selling, general and administrative expenses” for stock options. For the nine months ended September 30, 2019 and 2018, the Company recorded $3,611 and $3,182, respectively, in “Selling, general and administrative expenses” for stock options. As of September 30, 2019, the total compensation cost related to unvested stock options not yet recognized was $8,089. The cost will be amortized on a straight-line basis over the remaining weighted-average vesting period of 2.2 years.

Options	Number of Shares			Weighted Average Exercise Price
Outstanding at December 31, 2018		1,051,623		$	41.41
Granted		65,000			39.66
Exercised		(4,000	)		16.25
Forfeited or expired		(6,150	)		46.02
Outstanding at March 31, 2019		1,106,473			41.37
Granted		65,663			42.42
Exercised		(4,375	)		25.79
Forfeited or expired		(8,938	)		52.68
Outstanding at June 30, 2019		1,158,823			41.40
Exercised		(63,977	)		24.55
Forfeited or expired		(4,815	)		47.84
Outstanding at September 30, 2019		1,090,031			42.37
Exercisable at September 30, 2019		378,887		$	35.80

The aggregate intrinsic values for all stock options exercised for the three and nine months ended September 30, 2019 were $2,264 and $2,430, respectively. The aggregate intrinsic values for all stock options exercised for the three and nine months ended September 30, 2018 were $12,685 and $18,494, respectively. The aggregate intrinsic values for all stock options outstanding and exercisable as of September 30, 2019 were $18,677 and $8,980, respectively.

The following table is a summary of the Company’s nonvested stock options, restricted stock and performance shares for which the requisite service period has not been rendered but that are expected to vest on the achievement of a performance condition:

	Nonvested
	Stock Options					Restricted Stock				Performance Shares
	Number of Shares			Weighted- Average Grant-Date Fair Value		Number of Shares		Weighted- Average Grant-Date Fair Value		Number of Shares			Weighted- Average Grant-Date Fair Value
Nonvested at December 31, 2018		601,513		$	17.83		-	$	-		152,000		$	46.61
Granted		65,000			15.04		25,000		44.21		5,000			45.64
Vested during period		(7,000	)		9.26		-		-		-			-
Forfeited		(5,900	)		17.36		-		-		(5,750	)		40.65
Nonvested at March 31, 2019		653,613			17.65		25,000		44.21		151,250			46.80
Granted		65,663			16.40		15,729		40.06		-			-
Vested during period		(1,250	)		16.32		-		-		-			-
Forfeited		(2,067	)		17.50		-		-		(17,250	)		40.65
Nonvested at June 30, 2019		715,959			17.54		40,729		42.61		134,000			47.59
Forfeited		(4,815	)		18.00		-		-		(15,750	)		43.82
Nonvested at September 30, 2019		711,144		$	17.54		40,729	$	42.61		118,250		$	48.10

The Company granted restricted stock units during the nine months ended September 30, 2019 to certain executives which will vest over a two year period. Annually, members of the Cambrex Board of Directors are awarded restricted stock units that vest over six months. For the three months ended September 30, 2019 and 2018, the Company recorded $459 and $262, respectively, in “Selling, general and administrative expenses” for restricted stock units. For the nine months ended September 30, 2019 and 2018, the Company recorded $909 and $445, respectively, in “Selling, general and administrative expenses” for restricted stock units. As of September 30, 2019, total compensation cost related to nonvested restricted stock not yet recognized was $826. The cost will be amortized on a straight-line basis over the remaining weighted-average vesting period of 0.8 years.

The Company granted equity-settled performance shares (“PS”) to certain executives. PS awards provide the recipient the right to receive a certain number of shares of the Company’s common stock in the future, which depends on the Company’s level of achievement of net revenue and EBITDA growth as compared to the net revenue and EBITDA growth of the members of a specified peer group of companies over a three year period. For the three months ended September 30, 2019 and 2018, the Company recorded a benefit of $2 and $353, respectively, in “Selling, general and administrative expenses” related to performance shares. For the nine months ended September 30, 2019 and 2018, the Company recorded $445 and $479, respectively, in “Selling, general and administrative expenses” related to performance shares. As of September 30, 2019, total compensation cost related to nonvested performance shares not yet recognized was $2,480. The cost will be amortized on a straight-line basis over the remaining weighted-average vesting period of 1.2 years.