Short-Term Investments

3 Months Ended

Apr. 30, 2022

Investments, Debt and Equity Securities [Abstract]

At April 30, 2022, short-term investments consisted of the following (in thousands):


	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair value
Available-for-sale securities:
Certificates of deposits	$	63,710	$	13	$	(69)	$	63,654
Asset-backed securities	239,639		6		(3,465)		236,180
Commercial paper	151,341		14		(93)		151,262
Corporate notes and bonds	802,603		58		(15,100)		787,561
Foreign government bonds	24,521		4		(425)		24,100
U.S. agency obligations	27,982		10		(622)		27,370
U.S. treasury securities	312,468		20		(4,060)		308,428
Total available-for-sale securities	$	1,622,264	$	125	$	(23,834)	$	1,598,555

At January 31, 2022, short-term investments consisted of the following (in thousands):


	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair value
Available-for-sale securities:
Certificates of deposits	$	13,500	$	—	$	(15)	$	13,485
Asset-backed securities	191,676		45		(1,432)		190,289
Commercial paper	29,432		—		(2)		29,430
Corporate notes and bonds	669,489		276		(5,856)		663,909
Foreign government bonds	24,577		13		(179)		24,411
U.S. agency obligations	27,978		12		(254)		27,736
U.S. treasury securities	290,513		46		(1,755)		288,804
Total available-for-sale securities	$	1,247,165	$	392	$	(9,493)	$	1,238,064

The following table summarizes the estimated fair value of our short-term investments, designated as available-for-sale and classified by the contractual maturity date of the securities as of the dates shown (in thousands):


	April 30, 2022		January 31, 2022
Due in one year or less	$	666,232	$	457,948
Due in greater than one year	932,323		780,116
Total	$	1,598,555	$	1,238,064

We have not recorded an allowance for credit losses, as we believe any such losses would be immaterial based on the high credit quality of our investments. We intend to hold our securities to maturity and it is more likely than not that we will hold these securities until recovery of the cost basis.

The following table shows the fair values of available-for-sale securities which were in an unrealized loss position, aggregated by investment category, as of April 30, 2022 (in thousands):


	Held for less than 12 months
	Fair value		Gross unrealized losses
Certificates of deposits	$	33,641	$	(69)
Asset-backed securities	227,959		(3,465)
Commercial paper	112,904		(93)
Corporate notes and bonds	730,194		(15,100)
Foreign government bonds	20,516		(425)
U.S. agency obligations	24,360		(622)
U.S. treasury securities	270,888		(4,060)

The following table shows the fair values of available-for-sale securities which were in an unrealized loss position, aggregated by investment category, as of January 31, 2022 (in thousands):


	Held for less than 12 months
	Fair value		Gross unrealized losses

Certificates of deposits	$	5,985	$	(15)
Asset-backed securities	177,056		(1,432)
Commercial paper	17,190		(2)
Corporate notes and bonds	571,099		(5,856)
Foreign government bonds	19,594		(179)
U.S. agency obligations	24,725		(254)
U.S. treasury securities	247,509		(1,756)

Asset values and gross unrealized losses of available-for-sale securities held for more than 12 months as of April 30, 2022 and January 31, 2022 were immaterial.