Short-term investments. Gross unrealized gains and losses on our available-for-sale debt securities as of January 31, 2022 were not significant. The stated maturities of our available-for-sale debt securities as of January 31, 2022 were as follows:

As of January 31, 2022, the balances of our cash equivalents and short-term investments were as follows:


	Cost		Gross Unrealized Gains		Gross Unrealized Losses Less Than 12 Continuous Months		Gross Unrealized Losses 12 Continuous Months or Longer		Estimated Fair Value(1)
	(in thousands)
Cash equivalents:
Money market funds	$	75,680							$	75,680




Total:	$	75,680	$	—	$	—	$	—	$	75,680
Short-term investments:
U.S. government agency & T-bills	$	8,095			$	(31)			$	8,064
Municipal bonds	3,946				(34)				3,912


Corporate debt securities	103,946		5		(537)				103,414
Asset-backed securities	32,507		2		(151)				32,358


Total:	$	148,494	$	7	$	(753)	$	—	$	147,748

As of October 31, 2021, the balances of our cash equivalents and short-term investments were as follows:


	Cost		Gross Unrealized Gains		Gross Unrealized Losses Less Than 12 Continuous Months		Gross Unrealized Losses 12 Continuous Months or Longer		Estimated Fair Value(1)
	(in thousands)
Cash equivalents:
Money market funds	$	172,934	$	—	$	—	$	—	$	172,934



Total:	$	172,934	$	—	$	—	$	—	$	172,934
Short-term investments:
U.S. government agency & T-bills	$	6,447	$	—	$	(5)			$	6,442
Municipal bonds	4,588		—		(12)				4,576
Corporate debt securities	103,615		7		(170)				103,452
Asset-backed securities	33,545		6		(72)				33,479




Total:	$	148,195	$	13	$	(259)	$	—	$	147,949

Restricted cash. We include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the unaudited condensed consolidated statements of cash flows. All restricted cash is primarily associated with office leases.

The following table provided a reconciliation of cash, cash equivalents and restricted cash included in the unaudited condensed consolidated balance sheets:


	As of
	January 31, 2022		October 31, 2021
	(in thousands)
Cash and cash equivalents	$	1,124,299	$	1,432,840
Restricted cash included in prepaid expenses and other current assets	1,537		1,560
Restricted cash included in other long-term assets	749		783
Total cash, cash equivalents and restricted cash	$	1,126,585	$	1,435,183

Non-marketable equity securities. Our portfolio of non-marketable equity securities consists of strategic investments in privately held companies. There were no impairments of non-marketable equity securities during the three months ended January 31, 2022 and January 31, 2021.

We recognize derivative instruments as either assets or liabilities in the unaudited condensed consolidated balance sheets at fair value and provide qualitative and quantitative disclosures about such derivatives. We operate internationally and are exposed to potentially adverse movements in foreign currency exchange rates. We enter into hedges in the form of foreign currency forward contracts to reduce our exposure to foreign currency rate changes on non-functional currency denominated forecasted transactions and balance sheet positions including: (1) certain assets and liabilities, (2) shipments forecasted to occur within approximately one month, (3) future billings and revenue on previously shipped orders, and (4) certain future intercompany invoices denominated in foreign currencies.

The duration of forward contracts ranges from approximately one month to 24 months, the majority of which are short-term. We do not use foreign currency forward contracts for speculative or trading purposes. We enter into foreign exchange forward contracts with high credit quality financial institutions that are rated ‘A’ or above and to date have not experienced nonperformance by counterparties. In addition, we mitigate credit risk in derivative transactions by permitting net settlement of transactions with the same counterparty and anticipate continued performance by all counterparties to such agreements.

The assets or liabilities associated with the forward contracts are recorded at fair value in other current assets or accrued liabilities in the unaudited condensed consolidated balance sheets. The accounting for gains and losses resulting from changes in fair value depends on the use of the foreign currency forward contract and whether it is designated and qualifies for hedge accounting. The cash flow impact upon settlement of the derivative contracts will be included in net cash provided by operating activities in the unaudited condensed consolidated statements of cash flows.

Certain foreign exchange forward contracts are designated and qualify as cash flow hedges. These contracts have durations of approximately 24 months or less. Certain forward contracts are rolled over periodically to capture the full length of exposure to our foreign currency risk, which can be up to three years. To receive hedge accounting treatment, all hedging relationships are formally documented at the inception of the hedge, and the hedges must be highly effective in offsetting changes to future cash flows on the hedged transactions. The related gains or losses resulting from changes in fair value of these hedges is initially reported, net of tax, as a component of other comprehensive income (loss) (OCI) in stockholders’ equity and reclassified into revenue or operating expenses, as appropriate, at the time the hedged transactions affect earnings. We expect a majority of the hedge balance in OCI to be reclassified to the statements of income within the next 12 months.

Our foreign exchange forward contracts that are used to hedge non-functional currency denominated balance sheet assets and liabilities are not designated as hedging instruments. Accordingly, any gains or losses from changes in the fair value of the forward contracts are recorded in other income (expense), net. The gains and losses on these forward contracts generally offset the gains and losses associated with the underlying assets and liabilities, which are also recorded in other income (expense), net. The duration of the forward contracts for hedging our balance sheet exposure is approximately one month.

We also have certain foreign exchange forward contracts for hedging certain international revenues and expenses that are not designated as hedging instruments. Accordingly, any gains or losses from changes in the fair value of the forward contracts are recorded in other income (expense), net. The gains and losses on these forward contracts generally offset the gains and losses associated with the foreign currency in operating income. The duration of these forward contracts is usually less than one year. The overall goal of our hedging program is to minimize the impact of currency fluctuations on the net income over the fiscal year.

Our exposure to market gain or loss will vary over time as a function of currency exchange rates. The amounts ultimately realized upon settlement of these financial instruments, together with the gains and losses on the underlying exposures, will depend on actual market conditions during the remaining life of the instruments.

The following table represented the unaudited condensed consolidated balance sheets location and amount of derivative instrument fair values segregated between designated and non-designated hedge instruments:


	Fair values of derivative instruments designated as hedging instruments		Fair values of derivative instruments not designated as hedging instruments
	(in thousands)
Balance at January 31, 2022
Other current assets	$	17,498	$	57
Accrued liabilities	$	5,556	$	8
Balance at October 31, 2021
Other current assets	$	15,455	$	17
Accrued liabilities	$	2,027	$	42

The following table represented the location of the amount of gains and losses on derivative instrument fair values for designated hedge instruments, net of tax in the unaudited condensed consolidated statements of income:


	Location of gain (loss) recognized in OCI on derivatives	Amount of gain (loss) recognized in OCI on derivatives (effective portion)		Location of gain (loss) reclassified from OCI	Amount of gain (loss) reclassified from OCI (effective portion)
	(in thousands)
Three months ended January 31, 2022
Foreign exchange contracts	Revenue	$	(816)	Revenue	$	(571)
Foreign exchange contracts	Operating expenses	(769)		Operating expenses	(274)
Total		$	(1,585)		$	(845)
Three months ended January 31, 2021
Foreign exchange contracts	Revenue	$	(163)	Revenue	$	113
Foreign exchange contracts	Operating expenses	4,256		Operating expenses	2,613
Total		$	4,093		$	2,726