Cash Equivalents and Short-term Investments

12 Months Ended

Jan. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Cash Equivalents and Short-term Investments

The amortized cost, unrealized gain (loss) and estimated fair value of the Company’s cash equivalents and short-term investments as of January 31, 2020 and 2019 were as follows (in thousands):



	As of January 31, 2020
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	416,584	$	—	$	—		$	416,584
U.S. treasury securities	19,996		—		—			19,996
Total cash equivalents	436,580		—		—			436,580
Short-term investments:
U.S. treasury securities	575,920		686		(8		)	576,598
Corporate debt securities	305,859		519		—			306,378
Total short-term investments	881,779		1,205		(8		)	882,976
Total	$	1,318,359	$	1,205	$	(8	)	$	1,319,556



	As of January 31, 2019
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	247,426	$	—	$	—		$	247,426
Corporate debt securities	3,409		—		(1		)	3,408
Total cash equivalents	250,835		—		(1		)	250,834
Short-term investments:
U.S. treasury securities	195,913		37		(53		)	195,897
Corporate debt securities	69,483		13		(19		)	69,477
Total short-term investments	265,396		50		(72		)	265,374
Total	$	516,231	$	50	$	(73	)	$	516,208

All short-term investments were designated as available-for-sale securities as of January 31, 2020 and 2019.

The Company's short-term investments as of January 31, 2020 and 2019 all mature within one year, as follows (in thousands):



	As of January 31, 2020				As of January 31, 2019
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due within one year	$	881,779	$	882,976	$	265,396	$	265,374

The Company had 7 and 34 short-term investments in unrealized loss positions as of January 31, 2020 and 2019, 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, 2020, 2019 and 2018.

For available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) the Company has the intention to sell any of these investments and (ii) it is not more likely than not that the Company 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, 2020 and 2019.