v3.26.3
Stock-Based Compensation (Tables)
 9 Months Ended
Sep. 30, 2026
Share-Based Payment Arrangement [Abstract]  
Schedule of RSUs and PSUs to be Settled in Common Stock Activity
A summary of the activity for RSUs to be settled in common stock for the nine months ended September 30, 2026 and 2025 is as follows (RSUs in thousands):
20262025
RSUsWeighted Average
Grant Date Fair Value
(Per Unit)		RSUsWeighted Average
Grant Date Fair Value
(Per Unit)
Unvested at January 11,754 $226.392,024 $173.32
Granted526 $580.57575 $287.04
Vested(580)$225.95(692)$156.28
Forfeited(69)$227.81(91)$228.22
Unvested at September 30
1,631 $340.461,816 $213.15
A summary of the activity for PSUs to be settled in common stock for the nine months ended September 30, 2026 and 2025 is as follows (PSUs in thousands):
20262025
PSUsWeighted Average
Grant Date Fair Value
(Per Unit)		PSUsWeighted Average
Grant Date Fair Value
(Per Unit)
Unvested at January 1348 $224.15425 $177.69
Granted196 $790.2092 $259.17
Vested(149)$174.50(165)$123.88
Forfeited— N/A(4)$222.94
Unvested at September 30
395 $523.72348 $224.12
Grant Date Fair Value for Awards of Performance Units Inputs The Monte Carlo simulation valuation methodology applied to all the PSUs granted in 2026 and 2025 used the following key inputs:
20262025
Valuation date price based on closing stock prices of Quanta common stock on February 26, 2026, April 10, 2026 and September 1, 2026 for 2026 and February 27, 2025 for 2025
$565.05 to $611.39
$259.26
Expected volatility (1)
35% to 37%
34%
Risk-free interest rate
3.45% to 4.43%
4.05%
Term in years
2.85 to 4.73
2.84
(1)    The expected volatility inputs for Quanta are based on historical volatility, which is based on Quanta’s dividend-adjusted closing prices over a period equivalent to the performance period.