Earnings (Loss) per Share

12 Months Ended

Dec. 31, 2018

Earnings (Loss) per Share

Earnings (Loss) per Share

14.  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)	2016		2017		2018
Net loss for the period	$	(54,890)	$	(74,356)	$	(114,780)
Weighted average number of shares outstanding		21,478,320		29,830,669		50,795,768
Basic and diluted loss per share	$	(2.56)	$	(2.49)	$	(2.26)

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

	Year ended December 31,
	2016	2017	2018
Stock options	1,904,320	3,338,999	6,091,338
Restricted stock units	—	—	1,372,100