Stock-Based Compensation

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

12. STOCK-BASED COMPENSATION:

Restricted Stock Units (RSUs) to be Settled in Common Stock

A summary of the activity for RSUs to be settled in common stock for the nine months ended September 30, 2024 and 2023 is as follows (RSUs in thousands):


	2024		2023
	RSUs	Weighted Average Grant Date Fair Value (Per Unit)	RSUs	Weighted Average Grant Date Fair Value (Per Unit)
Unvested at January 1	2,548	$104.76	3,263	$78.74
Granted	812	$241.38	667	$161.42
Vested	(1,107)	$82.61	(1,199)	$66.14
Forfeited	(126)	$158.16	(119)	$114.47
Unvested at September 30	2,127	$165.61	2,612	$104.39

The approximate fair value of RSUs that vested during the nine months ended September 30, 2024 and 2023 was $282.2 million and $194.6 million.

During the nine months ended September 30, 2024 and 2023, Quanta recognized $83.6 million and $70.5 million of non-cash stock compensation expense related to RSUs to be settled in common stock. As of September 30, 2024, there was $232.7 million of total unrecognized compensation expense related to unvested RSUs to be settled in common stock granted to both employees and non-employees. This cost is expected to be recognized over a weighted average period of 2.91 years.

Performance Stock Units (PSUs) to be Settled in Common Stock

A summary of the activity for PSUs to be settled in common stock for the nine months ended September 30, 2024 and 2023 is as follows (PSUs in thousands):


	2024		2023
	PSUs	Weighted Average Grant Date Fair Value (Per Unit)	PSUs	Weighted Average Grant Date Fair Value (Per Unit)
Unvested at January 1	491	$129.70	733	$65.39
Granted	109	$263.34	177	$174.50
Vested	(175)	$96.45	(413)	$35.12
Forfeited	—	N/A	(6)	$101.66
Unvested at September 30	425	$177.69	491	$129.70

The Monte Carlo simulation valuation methodology applied the following key inputs:


	2024		2023
Valuation date price based on March 4, 2024 and March 9, 2023 closing stock prices of Quanta common stock	$243.34		$160.55
Expected volatility	33	%	35	%
Risk-free interest rate	4.43	%	4.62	%
Term in years	2.83		2.81

During the nine months ended September 30, 2024 and 2023, Quanta recognized $27.2 million and $24.2 million of non-cash stock compensation expense related to PSUs to be settled in common stock. As of September 30, 2024, there was an estimated $40.5 million of total unrecognized compensation expense related to unearned and unvested PSUs. This amount is based on forecasted attainment of performance metrics and estimated forfeitures of unearned and unvested PSUs. The compensation expense related to outstanding PSUs can vary from period to period based on changes in forecasted achievement of established performance goals and the total number of shares of common stock that Quanta anticipates will be issued upon vesting of such PSUs. This cost is expected to be recognized over a weighted average period of 1.80 years.

During the nine months ended September 30, 2024 and 2023, 0.3 million and 0.7 million shares of common stock were issued in connection with earned and vested PSUs. The approximate fair values of PSUs earned and vested during the nine months ended September 30, 2024 and 2023 were $75.4 million and $115.5 million, respectively.