Wesco’s stock-based compensation awards consist of stock options, stock-settled stock appreciation rights, restricted stock units and performance-based awards. Compensation cost for all stock-based awards is measured at fair value on the date of grant and compensation cost is recognized, net of estimated forfeitures, over the service period for awards expected to vest. The fair value of stock options and stock-settled stock appreciation rights is determined using the Black-Scholes model. The fair value of restricted stock units and performance-based awards with performance conditions is determined by the grant-date closing price of Wesco’s common stock. The forfeiture assumption is based on Wesco’s historical participant behavior that is reviewed on at least an annual basis. For stock options and stock-settled stock appreciation rights that are exercised, and for restricted stock units and performance-based awards that vest, shares are issued out of Wesco's outstanding common stock.

Stock options and stock-settled stock appreciation rights vest ratably over a three-year period and terminate on the tenth anniversary of the grant date unless terminated sooner under certain conditions. Restricted stock unit awards that were granted under the Company’s 1999 Long-Term Incentive Plan, as amended and restated, vest fully on the third anniversary of the date of grant, except for the special award described below, which vested in tranches. Restricted stock units awarded under the WESCO International, Inc. 2021 Omnibus Incentive Plan, which was adopted on May 27, 2021, vest ratably over a three-year period on each of the first, second and third anniversaries of the grant date. Vesting of performance-based awards is based on a three-year performance period, and the number of shares earned, if any, depends on the attainment of certain performance levels. Outstanding awards would vest upon the consummation of a change in control transaction with performance-based awards vesting at the target level.

On July 2, 2020, a special award of restricted stock units was granted to certain officers of the Company. These awards vested in tranches of 30% on each of the first and second anniversaries of the grant date and 40% on the third anniversary of the grant date, subject to continued employment through the applicable anniversary date.

Performance-based awards are based on two equally-weighted performance measures: the three-year average growth rate of Wesco's net income attributable to common stockholders and the three-year cumulative return on net assets. These awards are accounted for as awards with performance conditions; compensation cost is recognized over the performance period based upon Wesco's determination of whether it is probable that the performance targets will be achieved.

During the three and nine months ended September 30, 2023 and 2022, Wesco granted the following stock options, restricted stock units, and performance-based awards at the following weighted-average fair values:


	Three Months Ended				Nine Months Ended
	September 30, 2023		September 30, 2022		September 30, 2023		September 30, 2022
Stock options granted	1,593		3,249		78,729		92,799
Weighted-average fair value	$	72.57	$	54.13	$	76.69	$	57.15

Restricted stock units granted	1,649		1,669		175,513		226,615
Weighted-average fair value	$	140.91	$	112.33	$	170.13	$	122.04

Performance-based awards granted(1)	662		—		212,107		83,991
Weighted-average fair value(1)	$	115.04	$	—	$	86.97	$	122.09

(1) As described further below, the nine months ended September 30, 2023 includes performance-based awards granted in February 2020 for which actual achievement levels were certified in February 2023, as well as performance-based awards granted during the nine months ended September 30, 2023.


	Three Months Ended				Nine Months Ended
	September 30, 2023		September 30, 2022		September 30, 2023		September 30, 2022
Risk free interest rate	4.4	%	2.9	%	4.1	%	2.0	%
Expected life (in years)	5		7		5		7
Expected volatility	52	%	44	%	50	%	43	%
Expected dividend yield	0.96	%	n/a		0.89	%	n/a

The risk-free interest rate is based on the U.S. Treasury Daily Yield Curve rate as of the grant date. The expected life is based on historical exercise experience, the expected volatility is based on the volatility of the Company's daily stock price over the expected life preceding the grant date of the award, and the expected dividend yield is based on the calculated yield on the Company's common stock at date of grant using the current fiscal year projected dividend distribution rate. The Company did not pay dividends to holders of its common stock during the three and nine months ended September 30, 2022.


	Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In millions)
Outstanding at December 31, 2022	87,347	$	121.55
Granted	78,729	169.72
Exercised	(1,279)	122.09
Forfeited	(1,715)	148.67
Outstanding at September 30, 2023	163,082	$	144.51	8.9	$	2.0
Exercisable at September 30, 2023	28,411	$	121.53	8.4	$	0.6


	Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In millions)
Outstanding at December 31, 2022	1,248,115	$	62.02
Granted	—	—
Exercised	(428,500)	66.70
Forfeited	(1,331)	74.57
Outstanding at September 30, 2023	818,284	$	59.55	5.3	$	69.0
Exercisable at September 30, 2023	777,479	$	58.64	5.2	$	66.2


	Awards	Weighted- Average Fair Value
Unvested at December 31, 2022	774,233	$	73.79
Granted	175,513	170.13
Vested	(505,464)	59.43
Forfeited	(24,646)	122.66
Unvested at September 30, 2023	419,636	$	128.51


	Awards	Weighted- Average Fair Value
Unvested at December 31, 2022	335,329	$	75.26
Granted(1)	212,107	86.97
Vested	(289,394)	48.32
Forfeited	(3,732)	111.00
Unvested at September 30, 2023	254,310	$	115.15

(1) Includes 63,098 performance-based awards granted in February 2023 with a fair value of $171.96 and three-year performance period ending December 31, 2025, and 144,697 of additional performance-based awards related to awards originally granted in February 2020 with a fair value of $48.32 and three-year performance period ended December 31, 2022 for which actual achievement levels were certified in February 2023. Also includes 3,074 and 662 performance-based awards granted during the three months ended June 30, 2023 and September 30, 2023, respectively, with weighted-average fair values of $150.32 and $115.04, respectively, and three-year performance periods ending December 31, 2025.

Wesco recognized $10.8 million and $9.7 million of non-cash stock-based compensation expense for the three months ended September 30, 2023 and 2022, respectively, and $34.7 million and $34.4 million for the nine months ended September 30, 2023 and 2022, respectively, which is included in selling, general and administrative expenses for such periods. As of September 30, 2023, there was $60.1 million of total unrecognized compensation expense related to non-vested stock-based compensation arrangements for all awards previously made, which is expected to be recognized as follows: