The calculations of basic and diluted loss per share for the years ended December 31, 2023, 2022 and 2021 are as follows:


(In thousands, except for per share amounts)	2023			2022			2021
Numerator
Net Loss attributable to ADTRAN Holdings, Inc.	$	(267,688	)	$	(2,037	)	$	(8,635	)
Denominator
Weighted average number of shares – basic		78,416			62,346			48,582
Effect of dilutive securities:
Stock options		—			—			—
PSUs, RSUs and restricted stock		—			—			—
Weighted average number of shares – diluted		78,416			62,346			48,582
Loss per share attributable to ADTRAN Holdings, Inc. – basic	$	(3.41	)	$	(0.03	)	$	(0.18	)
Loss per share attributable to ADTRAN Holdings, Inc. – diluted	$	(3.41	)	$	(0.03	)	$	(0.18	)

For each of the years ended December 31, 2023, 2022 and 2021, less than 0.5 million, 0.1 million and 0.1 million shares of unvested or unearned, as applicable, PSUs, RSUs and restricted stock were excluded from the calculation of diluted loss per share due to their anti-dilutive effect.

For the years ended December 31, 2023, 2022 and 2021, 1.8 million, 0.2 million and 0.3 million stock options, respectively, were outstanding but were not included in the computation of diluted loss per share due to their exercise prices being greater than the average market price of the common shares during the quarter, making them anti-dilutive under the treasury stock method.