Our 2014 Equity Incentive Plan (the “Plan”), provides for grants of equity incentive awards to our executive officers, non-employee directors, eligible employees and other key persons in order to attract, motivate and retain the talent for which we compete. Under the Plan, awards may be granted up to a maximum of 17,142,857 shares, if all awards granted are “full value awards,” as defined, and up to 34,285,714 shares, if all of the awards granted are “not full value awards,” as defined. “Full value awards” are awards such as restricted stock or long-term incentive plan LTIP units of our Operating Partnership (“LTIP units”) that do not require the payment of an exercise price. “Not full value awards” are awards such as Appreciation Only LTIP units of our Operating Partnership (“AOLTIPs”), stock options or stock appreciation rights that require the payment of an exercise price. As of December 31, 2020, we have 7,001,002 shares available for future grants under the Plan, if all awards granted are full value awards, as defined in the Plan.

The following table summarizes the components of stock-based compensation expense for the years ended December 31, 2020, 2019 and 2018.


	For the Year Ended December 31,
(Amounts in thousands)	2020		2019		2018
LTIP units	$	10,463	$	11,860	$	9,059
Performance-based units		7,499		8,477		7,645
Restricted stock		1,217		1,228		988
Stock options		60		1,295		1,954
Total stock-based compensation expense	$	19,239	$	22,860	$	19,646

We grant our executive officers, non-employee directors and other employees LTIP units which vest over a period of three to five years and are subject to a taxable book-up event, as defined. The LTIP units granted in the years ended December 31, 2020, 2019 and 2018 had grant date fair values of $10,940,000, $13,091,000 and $10,145,000, respectively, which are being amortized into expense on a straight-line basis over the vesting period. As of December 31, 2020, there was $12,970,000 of total unrecognized compensation cost related to unvested LTIP units, which is expected to be recognized over a weighted-average period of 2.6 years. The following table summarizes our LTIP unit activity for the year ended December 31, 2020.

	Units			Weighted-Average Grant-Date Fair Value
Unvested as of December 31, 2019		1,571,464		$	13.30
Granted		931,855			11.74
Vested		(778,510	)		13.51
Cancelled or expired		-			-
Unvested as of December 31, 2020		1,724,809		$	12.36

We grant our executive officers and other employees LTIP units under multi-year performance-based long-term equity compensation programs. The purpose of these Performance Programs is to further align the interests of our stockholders with that of management by encouraging our senior officers to create stockholder value in a “pay for performance” structure. Under the Performance Programs, participants may earn LTIP units based on our Total Shareholder Return (“TSR”) over a three-year performance measurement period on both an absolute basis and relative basis. If the designated performance objectives are achieved, awards earned under the Performance Programs are subject to vesting over a period of four years and are also subject to a taxable book-up event, as defined.

The LTIP units granted under the Performance Programs in the years ended December 31, 2020, 2019 and 2018 had grant date fair values of $7,488,000, $8,106,000 and $7,009,000, respectively, and are being amortized into expense over the four-year vesting period using a graded vesting attribution method. As of December 31, 2020, there was $8,999,000 of total unrecognized compensation cost related to unvested LTIP units granted under the Performance Programs, which is expected to be recognized over a weighted average period of 2.1 years. The following table summarizes our LTIP unit activity granted under the Performance Programs for the year ended December 31, 2020.

	Units			Weighted-Average Grant-Date Fair Value (per unit)
Unvested as of December 31, 2019		3,595,834		$	6.54
Granted		1,068,693			7.01
Earned and Vested		(216,005	)		9.71
Cancelled or expired		(667,730	)		9.71
Unvested as of December 31, 2020		3,780,792		$	5.93

The three-year performance measurement period with respect to our 2016 Performance Program ended on December 31, 2019. On January 17, 2020, the Compensation Committee of our Board of Directors (the “Compensation Committee”) determined that (i) the performance goals were not met on an absolute TSR basis and (ii) the performance goals met the 30^th percentile of the performance of the SNL U.S. Office REIT Index constituents on a relative basis. Accordingly, of the 1,085,244 LTIP units that were granted under the 2016 Performance Program, 216,005 LTIP units, or approximately 19.9% of the total units granted, were earned. Of the LTIP units that were earned, 107,996 LTIP units vested immediately on January 17, 2020 and the remaining 108,009 LTIP units vested on December 31, 2020. This award had a grant date fair value of $10,520,000 that was amortized into expense over the four-year vesting period through December 31, 2020 using a graded vesting distribution method.

On January 17, 2020, the Compensation Committee approved the 2019 Performance Program, a multi-year performance-based long-term incentive compensation program. Under the 2019 Performance Program, participants may earn awards in the form of LTIP units based on our TSR over a three-year performance measurement period beginning on January 1, 2020 and continuing through December 31, 2022. Specifically, 50.0% of the awards would be earned based on the rank of our TSR relative to the TSR of our Central Business District focused New York City office peers, comprised of Vornado Realty Trust, SL Green Realty Corp., Empire State Realty Trust and Columbia Property Trust, and the remaining 50.0% of the awards would be earned based on the percentile rank of our TSR relative to performance of the SNL U.S. Office REIT Index constituents. Furthermore, if our TSR is negative over the three-year performance measurement period, then the number of LTIP units that are earned under the 2019 Performance Program will be reduced by 30.0% of the number of such awards that otherwise would have been earned. Additionally, if the designated performance objectives are achieved, awards earned under the 2019 Performance Program are subject to vesting based on continued employment with us through December 31, 2023, with 50.0% of each award vesting upon the conclusion of the performance measurement period, and the remaining 50.0% vesting on December 31, 2023. Lastly, our Named Executive Officers are required to hold earned awards for an additional year following vesting. The fair value of the awards granted under the 2019 Performance Program on the date of the grant was $7,488,000 and is being amortized into expense over the four-year vesting period using a graded vesting attribution method.

We grant shares of restricted stock to a non-employee director and certain other employees which vest over four years. The shares of restricted stock granted in the years ended December 31, 2020, 2019 and 2018 had grant date fair values of $1,209,000, $1,238,000 and $1,335,000, respectively, which are being amortized into expense on a straight-line basis over the vesting period. As of December 31, 2020, there was $1,696,000 of total unrecognized compensation cost related to restricted stock, which is expected to be recognized over a weighted-average period of 2.3 years. The table below summarizes our restricted stock activity for the year ended December 31, 2020.

	Shares			Weighted-Average Grant-Date Fair Value
Unvested as of December 31, 2019		168,470		$	14.27
Granted		92,424			13.08
Vested		(75,895	)		14.71
Cancelled or expired		(16,291	)		14.09
Unvested as of December 31, 2020		168,708		$	13.44

We did not grant any stock options in the years ended December 31, 2020, 2019 and 2018. Stock options granted in prior years to certain of our executive officers and other employees vest over periods ranging from three to five years and expire 10 years from the date of grant. In the year ended December 31, 2020, we have recognized the remaining $60,000 of compensation cost related to unvested stock options.

The following table summarizes our stock option activity for the year ended December 31, 2020.

	Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2019		2,084,943		$	17.07
Granted		-			-
Exercised		-			-
Cancelled or expired		(52,450	)		17.50
Outstanding as of December 31, 2020		2,032,493		$	17.06		4.7	$	-
Options vested and expected to vest as of December 31, 2020		2,032,493		$	17.06		4.7	$	-
Options exercisable as of December 31, 2020		2,032,493		$	17.06		4.7	$	-