On May 25, 2017, the shareholders of the Company approved an amendment to the Equity Incentive Plan, originally effective as of October 14, 2003, and previously amended and restated and approved by the shareholders on December 21, 2015 (the “Amended Plan”). The Amended Plan allows for the award of equity incentives, including stock options, stock appreciation rights, restricted stock awards, stock bonus awards, deferred stock awards, and other stock-based awards to certain employees, directors, or officers of, or key non-employee advisers or consultants, including contracted physicians to the Company or its subsidiaries. The Amended Plan, provides that the maximum aggregate number of shares of the Company’s common stock reserved and available for issuance under the Amended Plan is 18,650,000.

As of December 31, 2019 and 2018, stock options outstanding totaled 5.3 million and 6.8 million shares, respectively. As of December 31, 2019 and 2018, a total of approximately 2.3 million and 3.3 million shares, respectively, were available for future option and stock awards under the Amended Plan. Options typically expire after 5 or 7 years and generally vest over 3 or 4 years, but each grant’s expiration, vesting and exercise price provisions are determined at the time the awards are granted by the Compensation Committee of the Board of Directors.

The fair value of each stock option award granted during the years ended December 31, 2019, 2018 and 2017 was estimated as of the grant date using a trinomial lattice model with the following weighted average assumptions:


	2019			2018			2017
Expected term (in years)	3.0 – 5.5			1.6 – 4.0			3.0 – 4.5
Risk-free interest rate (%)	2.4		%	2.5		%	1.5		%
Expected volatility (%)	43.2		%	43.0		%	49.0		%
Dividend yield (%)	0.0		%	0.0		%	0.0		%
Weighted average fair value/share at grant date	$	5.77		$	2.80		$	2.26


	Number of Shares	Weighted Average Exercise Price
Outstanding at December 31, 2016	5,136,110	$	5.76
Granted	2,119,498	7.60
Exercised	(565,569)	3.84
Forfeited	(347,513)	6.12
Outstanding at December 31, 2017	6,342,526	6.51
Granted	2,457,102	9.03
Exercised	(1,570,211)	5.48
Forfeited	(390,000)	7.15
Outstanding at December 31, 2018	6,839,417	7.63
Granted	969,720	19.70
Exercised	(2,309,451)	6.83
Forfeited	(180,927)	13.34
Outstanding at December 31, 2019	5,318,759	9.97
Exercisable at December 31, 2019	2,261,999	7.48

The number and weighted average grant-date fair values of options non-vested at the beginning and end of 2019, as well as options granted, vested and forfeited during the year was as follows:


	Number of Options	Weighted Average Grant Date Fair Value
Non-vested at December 31, 2018	4,330,526	$	2.67
Granted	969,720	5.77
Vested	(2,067,559)	2.67
Forfeited	(175,928)	4.09
Non-vested at December 31, 2019	3,056,759	3.60


	Options Outstanding						Options Exercisable
Range of Exercise Prices ($)	Number Outstanding	Weighted Average Remaining Contractual Life (Years)	Weighted Average Exercise Price		Number Exercisable	Weighted Average Remaining Contractual Life (Years)	Weighted Average Exercise Price
3.31 – 6.00	274,500	0.39	$	4.84	274,500	0.39	$	4.84
6.01 – 7.00	210,417	1.08	6.78		182,917	0.06	6.77
7.01 – 8.00	1,697,935	2.05	7.39		1,129,420	1.92	7.36
8.01 – 9.00	1,561,425	3.00	8.02		454,167	2.66	7.97
9.01 – 14.00	690,686	3.51	11.07		216,662	3.40	10.91
14.01 – 26.42	883,796	4.93	19.86		4,333	3.70	14.25
	5,318,759	2.87	9.97		2,261,999	1.96	7.48

As of December 31, 2019, the aggregate intrinsic value of all stock options outstanding and expected to vest was approximately $102.5 million and the aggregate intrinsic value of currently exercisable stock options was approximately $49.2 million. The intrinsic value of each option share is the difference between the fair market value of NeoGenomics’ common stock and the exercise price of such option share to the extent it is “in-the-money”. Aggregate intrinsic value represents the value that would have been received by the holders of in-the-money options had they exercised their options on the last trading day of the year

and sold the underlying shares at the closing stock price on such day. The intrinsic value calculation is based on the $29.25 closing stock price of NeoGenomics Common Stock on December 31, 2019, the last trading day of 2019. The total number of in-the-money options outstanding and exercisable as of December 31, 2019 was approximately 2.3 million.

The total intrinsic value of options exercised during the years ended December 31, 2019, 2018 and 2017 was approximately $35.3 million, $29.3 million and $2.8 million, respectively. Intrinsic value of exercised shares is the total value of such shares on the date of exercise less the cash received from the option holder to exercise the options. The total cash proceeds received from the exercise of stock options was approximately $12.4 million, $8.6 million and $2.2 million for the years ended December 31, 2019, 2018 and 2017, respectively.

The total fair value of options granted during the years ended December 31, 2019, 2018 and 2017 was approximately $5.6 million, $6.9 million and $4.8 million, respectively. The total fair value of option shares vested during the years ended December 31, 2019, 2018 and 2017 was approximately $5.5 million, $5.5 million and $3.6 million, respectively.

We recognize stock-based compensation expense using the straight-line basis over the awards’ requisite service periods. Stock compensation expense related to stock options for the years ended December 31, 2019, 2018 and 2017 was approximately $6.8 million, $5.4 million and $5.0 million, respectively. As of December 31, 2019, there was approximately $4.6 million of total unrecognized stock-based compensation cost related to non-vested stock options granted under the Amended Plan. This cost is expected to be recognized over a weighted-average period of 1.5 years.

The Company sponsors an Employee Stock Purchase Plan (“ESPP”), under which eligible employees can purchase common stock at a 15% discount from the fair market value. Stock-based compensation expense related to the ESPP for the years ended December 31, 2019, 2018 and 2017 was approximately $0.6 million, $0.2 million and $0.1 million, respectively. Shares issued pursuant to this plan were 141,908, 113,503 and 108,599 for the years ended December 31, 2019, 2018 and 2017, respectively.

The number and weighted average grant date fair values of restricted non-vested common stock at the beginning and end of 2019, 2018 and 2017, as well as stock awards granted, vested and forfeited during the year are as follows:


	Number of Restricted Shares	Weighted Average Grant Date Fair Value
Nonvested at December 31, 2016	137,244	$	3.59
Granted in 2017	372,711	7.27
Vested in 2017	(182,744)	4.50
Forfeited in 2017	—	—
Nonvested at December 31, 2017	327,211	7.27
Granted in 2018	87,811	12.87
Vested in 2018	(119,180)	7.27
Forfeited in 2018	(13,334)	7.27
Nonvested at December 31, 2018	282,508	9.01
Granted in 2019	230,980	19.93
Vested in 2019	(115,711)	9.36
Forfeited in 2019	(62,479)	12.53
Nonvested at December 31, 2019	335,298	15.75

Stock compensation expense related to restricted stock for the years ended December 31, 2019, 2018 and 2017 was approximately $2.6 million, $1.3 million, and $1.3 million, respectively. As of December 31, 2019, there was approximately $2.9 million of total unrecognized stock-based compensation cost related to non-vested restricted stock granted under the Amended Plan. This cost is expected to be recognized over a weighted-average period of 1.4 years.