Cash Equivalents and Short-term Investments

The amortized costs, unrealized gains and losses and estimated fair values of the Company’s cash equivalents and short-term investments as of January 31, 2018 and 2017 were as follows (in thousands):



	As of January 31, 2018
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	90,770	$	—	$	—		$	90,770
Total cash equivalents	$	90,770	$	—	$	—		$	90,770
Short-term investments:
Commercial paper	$	15,946	$	—	$	—		$	15,946
U.S. treasury securities	61,896		—		(158		)	61,738
Corporate debt securities	24,125		—		(44		)	24,081
Total short-term investments	101,967		—		(202		)	101,765
Total	$	192,737	$	—	$	(202	)	$	192,535



	As of January 31, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	10,565	$	—	$	—		$	10,565
Total cash equivalents	$	10,565	$	—	$	—		$	10,565
Short-term investments:
Asset-backed securities	$	1,538	$	—	$	—		$	1,538
Corporate debt securities	12,842		13		(3		)	12,852
Total short-term investments	14,380		13		(3		)	14,390
Total	$	24,945	$	13	$	(3	)	$	24,955

All short-term investments were designated as available-for-sale securities as of January 31, 2018 and 2017.

The following tables present the contractual maturities of the Company’s short-term investments as of January 31, 2018 and 2017 (in thousands):



	As of January 31, 2018				As of January 31, 2017
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due within one year	$	93,421	$	93,237	$	12,842	$	12,852
Due between one to five years	8,546		8,528		1,538		1,538
	$	101,967	$	101,765	$	14,380	$	14,390

The Company had 23 and five short-term investments in unrealized loss positions as of January 31, 2018 and 2017, respectively. There were no material gross unrealized gains or losses from available-for-sale securities and no material realized gains or losses from available-for-sale securities that were reclassified out of accumulated other comprehensive income for the years ended January 31, 2018, 2017 or 2016.

For available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) it has the intention to sell any of these investments and (ii) whether it is not more likely than not that it will be required to sell any of these available-for-sale debt securities before recovery of the entire amortized cost basis. Based on this evaluation, the Company determined that there were no other-than-temporary impairments associated with short-term investments as of January 31, 2018 and 2017.