Earnings Per Share

12 Months Ended

Dec. 31, 2020

Earnings Per ShareBasic net income per share attributable to Vertex common shareholders is based upon the weighted-average number of common shares outstanding during the period. Diluted net income per share attributable to Vertex common shareholders utilizing the treasury-stock method is based upon the weighted-average number of common shares outstanding during the period plus additional weighted-average common equivalent shares outstanding during the period when the effect is dilutive.

The following table sets forth the computation of basic and diluted net income per share for the periods ended:


	2020		2019		2018
	(in thousands, except per share amounts)
Basic net income attributable to Vertex per common share calculation:
Net income attributable to Vertex common shareholders	$	2,711,647	$	1,176,810	$	2,096,896
Less: Undistributed earnings allocated to participating securities	—		—		(501)
Net income attributable to Vertex common shareholders—basic	$	2,711,647	$	1,176,810	$	2,096,395

Basic weighted-average common shares outstanding	259,841		256,728		254,292
Basic net income attributable to Vertex per common share	$	10.44	$	4.58	$	8.24

Diluted net income attributable to Vertex per common share calculation:
Net income attributable to Vertex common shareholders	$	2,711,647	$	1,176,810	$	2,096,896
Less: Undistributed earnings allocated to participating securities	—		—		(492)
Net income attributable to Vertex common shareholders—diluted	$	2,711,647	$	1,176,810	$	2,096,404

Weighted-average shares used to compute basic net income per common share	259,841		256,728		254,292
Effect of potentially dilutive securities:
Stock options	1,801		2,231		2,913
Restricted stock units (including PSUs) and restricted stock	1,741		1,700		1,963
Employee stock purchase program	13		14		17
Weighted-average shares used to compute diluted net income per common share	263,396		260,673		259,185
Diluted net income attributable to Vertex per common share	$	10.29	$	4.51	$	8.09

The Company did not include the securities in the following table in the computation of the net income per share attributable to Vertex common shareholders calculations because the effect would have been anti-dilutive during each period.


	2020	2019	2018
	(in thousands)
Stock options	312	2,833	2,217
Unvested restricted stock units (including PSUs) and restricted stock	257	6	5