Investments (Tables)

6 Months Ended

Jun. 30, 2018

Investments Disclosure [Abstract]

Summary of Investments Included in Cash Equivalents and Short Term Investments

The following table summarizes the Company’s investments, which are included in cash equivalents and short-term investments, as of June 30, 2018 and December 31, 2017:

As of June 30, 2018	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Money market mutual funds	$	35,781,822	$	—	$	—		$	35,781,822
Asset-backed securities		20,160,567		1,279		(2,074	)		20,159,772
Commercial paper		85,895,613		—		—			85,895,613
Corporate debt securities		64,147,033		813		(35,971	)		64,111,875
U.S. Treasury securities		49,008,349		55		(12,748	)		48,995,656
Total	$	254,993,384	$	2,147	$	(50,793	)	$	254,944,738
As of December 31, 2017	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Money market mutual funds	$	44,181,756	$	—	$	—		$	44,181,756
Asset-backed securities		7,428,021		—		(6,318	)		7,421,703
Commercial paper		34,882,298		—		—			34,882,298
Corporate debt securities		26,905,815		—		(49,532	)		26,856,283
U.S. Treasury securities		8,940,778		—		(17,458	)		8,923,320
Total	$	122,338,668	$	—	$	(73,308	)	$	122,265,360