Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Schedule of assets measured at fair value on a recurring basis

The following tables present the Company’s financial assets and liabilities measured and recorded at fair value on a recurring basis using the above input categories as of March 31, 2019 and December 31, 2018:



	Quoted Price
	in Active	Significant
	Market for	Other	Significant
	Identical	Observable	Unobservable
	Assets	Inputs	Inputs
As of March 31, 2019	(Level 1)	(Level 2)	(Level 3)
	$	$	$
Short-term investments (Note 5):
U.S. treasury securities	825,435	—	—
U.S. agency securities	23,732	—	—
Cash equivalents
U.S. treasury securities	124,856	—	—
Money market funds	59,884	—	—
Total	1,033,907	—	—



	Quoted Price
	in Active	Significant
	Market for	Other	Significant
	Identical	Observable	Unobservable
	Assets	Inputs	Inputs
As of December 31, 2018	(Level 1)	(Level 2)	(Level 3)
	$	$	$
Short-term investments (Note 5):
U.S. treasury securities	1,068,509	—	—
Cash equivalents
Money market funds	159,810	—	—
Total	1,228,319	—	—