Shareholders' Equity (Tables)

The following table summarizes the stock option and RSU award activities under the Company's share-based compensation plans for the years ended December 31, 2015, 2014, and 2013:



	Shares Subject to Options Outstanding						Outstanding RSUs
	Number of Options⁽¹⁾		Weighted Average Exercise Price $	Remaining Contractual Term (in years)	Aggregate Intrinsic Value ⁽²⁾ $	Weighted Average Grant Date Fair Value $	Outstanding RSUs		Weighted Average Grant Date Fair Value $
Balance as at December 31, 2013	12,737,893		0.38	—	—	—	—		—
Stock options granted	2,985,495		5.28	—	—	5.63	—		—
Stock options exercised	(305,649	)	0.46	—	—	—	—		—
Stock options forfeited	(386,351	)	1.40	—	—	—	—		—
Balance as at December 31, 2014	15,031,388		1.31	7.16	73,642	—	—		—

Stock options granted	1,259,025		22.16	—	—	12.16	—		—
Stock options exercised	(4,665,059	)	0.34	—	—	—	—		—
Stock options forfeited	(421,328	)	12.04	—	—	—	—		—
RSUs granted	—		—	—	—	—	503,701		32.01
RSUs settled	—		—	—	—	—	—		—
RSUs forfeited	—		—	—	—	—	(75,135	)	30.95
Balance as at December 31, 2015	11,204,026		3.65	6.99	248,119	—	428,566		32.19
Stock options exercisable as of December 31, 2015	6,902,359		0.82	6.03	172,415

(1) As at December 31, 2015 10,519,901 of the outstanding stock options were granted under the Company's Legacy Option Plan and are exercisable for Class B multiple voting shares, and 684,125 of the outstanding stock options were granted under the Company's Stock Option Plan and are exercisable for Class A subordinate voting shares.

(2) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock option awards and the assessed fair value of the common stock as of December 31, 2014 and the closing market price of our common stock as of December 31, 2015.

The assumptions used to estimate the fair value of stock options granted to employees are as follows:



	2015		2014		2013
Expected volatility	64.3	%	62.4	%	73.9	%
Risk free interest rate	1.62	%	1.82	%	1.67	%
Dividend yield	Nil		Nil		Nil
Average expected life	5.26		5.73		6.06

The following table illustrates the classification of stock-based compensation in the Consolidated Statements of Operations and Comprehensive Loss, which includes both stock-based compensation and restricted share-based compensation expense.



	Years ended
	December 31, 2015	December 31, 2014	December 31, 2013
	$	$	$
Cost of revenues	282	259	113
Sales and marketing	1,099	696	354
Research and development	4,509	2,776	1,152
General and administrative	2,268	712	147
	8,158	4,443	1,766