5. Earnings (Loss) per Common Share

Basic earnings (loss) per common share is computed by dividing net income attributable to Novanta Inc. after adjustment of redeemable noncontrolling interest to estimated redemption value by the weighted average number of common shares outstanding during the period. The Company recognizes changes in the redeemable noncontrolling interest redemption value by adjusting the carrying amount of the redeemable noncontrolling interest as of the end of the period to the higher of: (i) the estimated redemption value assuming the end of the period is also the redemption date or (ii) the carrying value without any redemption value adjustments. Such adjustments are recorded in retained earnings in stockholders’ equity instead of net income attributable to Novanta Inc. For both basic and diluted earnings (loss) per common share, such redemption value adjustments are included in the calculation of the numerator. For diluted earnings (loss) per common share, the denominator also includes the dilutive effect of outstanding restricted stock units, stock options and total shareholder return performance restricted stock units determined using the treasury stock method. Dilutive effects of contingently issuable shares are included in the weighted average dilutive share calculation using the treasury stock method when the contingencies have been resolved. For periods in which net losses are generated, the dilutive potential common shares are excluded from the calculation of diluted earnings per common share as the effect would be anti-dilutive.

The following table sets forth the computation of basic and diluted earnings (loss) per common share (in thousands, except per share amounts):

	Three Months Ended					Nine Months Ended
	September 29,			September 30,		September 29,			September 30,
	2017			2016		2017			2016
Numerators:
Income from continuing operations	$	8,366		$	7,470	$	52,630		$	14,247
Less: Net income attributable to noncontrolling interest		(834	)		—		(1,444	)		—
Net income attributable to Novanta Inc.		7,532			7,470		51,186			14,247
Less: Adjustment of redeemable noncontrolling interest to estimated redemption value (see Note 14)		(7,585	)		—		(11,303	)		—
Net income (loss) attributable to Novanta Inc. after adjustment of redeemable noncontrolling interest to estimated redemption value	$	(53	)	$	7,470	$	39,883		$	14,247

Denominators:
Weighted average common shares outstanding— basic		34,833			34,677		34,809			34,689
Dilutive potential common shares ⁽¹⁾		—			251		426			200
Weighted average common shares outstanding— diluted		34,833			34,928		35,235			34,889
Antidilutive common shares excluded from above		—			144		—			112

Basic Earnings (Loss) per Common Share:
Basic earnings (loss) per common share attributable to Novanta Inc.	$	(0.00	)	$	0.22	$	1.15		$	0.41

Diluted Earnings (Loss) per Common Share:
Diluted earnings (loss) per common share attributable to Novanta Inc.	$	(0.00	)	$	0.21	$	1.13		$	0.41

(1)

Due to the Company’s net loss position after adjustment of redeemable noncontrolling interest to estimated redemption value for the three months ended September 29, 2017, all potentially dilutive shares are excluded from the calculation of the denominator as their effect would have been anti-dilutive.

Common Share Repurchases

During the nine months ended September 29, 2017, the Company repurchased 14 thousand of its common shares in the open market for an aggregate purchase price of $0.4 million at an average price of $26.41 per share.