Profit per share

12 Months Ended

Dec. 31, 2020


Computations of profit per share:
(Dollars in millions except per share data)	2020		2019		2018
Profit for the period (A) 1	$	2,998	$	6,093	$	6,147
Determination of shares (in millions):
Weighted average number of common shares outstanding (B)	544.1		561.6		591.4
Shares issuable on exercise of stock awards, net of shares assumed to be purchased out of proceeds at average market price	4.5		5.9		8.0
Average common shares outstanding for fully diluted computation (C) 2	548.6		567.5		599.4
Profit per share of common stock:
Assuming no dilution (A/B)	$	5.51	$	10.85	$	10.39
Assuming full dilution (A/C) 2	$	5.46	$	10.74	$	10.26
Shares outstanding as of December 31 (in millions)	545.3		550.1		575.5

1Profit attributable to common shareholders.

2Diluted by assumed exercise of stock-based compensation awards using the treasury stock method.

For the year ended December 31, 2020, 2019 and 2018, we excluded 4.6 million, 3.0 million and 1.5 million outstanding stock options, respectively, from the computation of diluted earnings per share because the effect would have been antidilutive.

In July 2018, the Board approved a new share repurchase authorization of up to $10.0 billion of Caterpillar common stock effective January 1, 2019, with no expiration. As of December 31, 2020, approximately $4.8 billion remained available under the 2018 Authorization.

During 2020, 2019 and 2018, we repurchased 10.1 million, 30.6 million and 27.7 million shares of Caterpillar common stock, respectively, at an aggregate cost of $1.3 billion, $4.0 billion and $3.8 billion respectively. We made these purchases through a combination of accelerated stock repurchase agreements with third-party financial institutions and open market transactions.