Earnings (Loss) per Share

12 Months Ended

Dec. 31, 2017

13. Earnings (Loss) per Share

Basic and diluted loss per share

Basic and diluted loss per share is calculated by dividing the net loss attributable to shareholders by the weighted average number of shares outstanding during the year. Diluted net loss per share is the same as basic net loss per share during the periods presented as the effects of the Company's common stock equivalents are antidilutive and thus not included in the calculation.

	Year ended December 31,
(in thousands, except per share data)	2015			2016			2017
Net loss for the period	$	(46,964	)	$	(54,890	)	$	(74,356	)
Adjustment to redemption value of silent partnerships		(3,875	)		—			—

Net loss attributable to shareholders		(50,839	)		(54,890	)		(74,356	)
Weighted average number of shares outstanding		10,583,950			21,478,320			29,830,669
Excluded treasury shares on December 31		2,819			—			—

Basic and diluted loss per share	$	(4.80	)	$	(2.56	)	$	(2.49	)

The following common stock equivalents were excluded from the calculations of diluted loss per share as their effect would be anti-dilutive:

	Year ended December 31,
	2015		2016		2017
Stock options		1,327,060		1,904,320		3,338,999