Short-Term Investments

3 Months Ended

Mar. 31, 2019

3. SHORT-TERM INVESTMENTS

The Company invests its excess cash in fixed income instruments denominated and payable in U.S. dollars including U.S. treasury securities, commercial paper, corporate debt securities and asset-backed securities in accordance with the Company’s investment policy that primarily seeks to maintain adequate liquidity and preserve capital.

The Company has designated all investments as available-for-sale and therefore such investments are reported at fair value. Unrealized gains or losses on investments are recorded in accumulated other comprehensive income or loss, a component of stockholders’ equity (deficit), on the Company’s condensed consolidated balance sheets.

The following table summarizes the Company’s investments, which are included in cash equivalents and short-term investments:

As of March 31, 2019	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market mutual funds	$	40,291	$	—	$	—		$	40,291
Asset-backed securities		18,078		2		(1	)		18,079
Commercial paper		56,350		—		—			56,350
Corporate debt securities		45,887		6		(9	)		45,884
U.S. Treasury securities		26,876		8		—			26,884
Total	$	187,482	$	16	$	(10	)	$	187,488

As of December 31, 2018	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market mutual funds	$	31,740	$	—	$	—		$	31,740
Asset-backed securities		19,541		—		(21	)		19,520
Commercial paper		78,571		—		—			78,571
Corporate debt securities		54,511		—		(50	)		54,461
U.S. Treasury securities		29,980		—		(6	)		29,974
Total	$	214,343	$	—	$	(77	)	$	214,266

As of March 31, 2019, the Company does not consider those securities that are in an unrealized loss position to be other-than-temporarily impaired, as it has the ability to hold such investments until recovery of the fair value. The Company utilizes the specific identification method in computing realized gains and losses. The Company had no realized gains and losses on its available-for-sale securities for the three months ended March 31, 2019 and 2018. The contractual maturity dates of all of the Company’s investments are less than one year.