BALANCE SHEET COMPONENTS

Short-Term Investments—The amortized cost of our short-term investments approximate their fair value. As of July 31, 2017 and October 31, 2017, unrealized gains or losses from our short-term investments were immaterial and there were no securities in an unrealized loss position for more than 12 months.

The following table summarizes the estimated fair value of our investments in marketable debt securities, by the contractual maturity date:



	As of October 31, 2017
	(in thousands)
Due within 1 year	$	153,044
Due after 1 year through 3 years	80,442
Total	$	233,486

Property and Equipment—Net—Property and equipment, net consists of the following:



	Estimated Useful Life (In months)	As of
	Estimated Useful Life (In months)	July 31, 2017			October 31, 2017
		(in thousands)
Computer, production, engineering and other equipment	36	$	85,280		$	97,027
Demonstration units	12	46,387			49,109
Leasehold improvements	*	10,562			14,605
Furniture and fixtures	60	4,744			5,483
Total property and equipment—gross		146,973			166,224
Less accumulated depreciation and amortization		(88,901		)	(98,649		)
Total property and equipment—net		$	58,072		$	67,575

____________


*	Leasehold improvements are amortized over the shorter of the estimated useful lives of the improvements or the remaining lease term.

Depreciation and amortization expense related to our property and equipment was $8.2 million and $10.2 million for the three months ended October 31, 2016 and 2017, respectively.

Intangible Assets—Net—Intangible assets, net consists of the following:



	As of
	July 31, 2017			October 31, 2017
	(in thousands
Indefinite-lived intangible asset:
In-process R&D*	$	16,100		$	—
Finite-lived intangible assets:
Developed technology*	7,300			23,400
Customer relationships	4,830			4,830
Total finite-lived intangible assets, gross	12,130			28,230
Total intangible assets, gross	28,230			28,230
Less:
Accumulated amortization of developed technology	(1,314		)	(2,209		)
Accumulated amortization of customer relationships	(915		)	(1,126		)
Total accumulated amortization	(2,229		)	(3,335		)
Intangible assets, net	$	26,001		$	24,895

* We started amortizing the in-process R&D during the first quarter of fiscal 2018 because the related technology was completed and released in the first quarter of fiscal 2018. We are amortizing the developed technology using the straight-line method over a useful life of 5 years. Based on the foregoing, the balance of in-process R&D is now presented as part of developed technology under finite-lived intangible assets as of October 31, 2017.

The amortization expense of finite-lived intangible assets is being recognized in the condensed consolidated statement of operations within product cost of revenue for developed technology and sales and marketing expenses for customer relationships.

Estimated future amortization expense of finite-lived intangible assets is as follows:



Year Ending July 31:	(In thousands)
2018 (remaining nine months)	$	4,066
2019	5,421
2020	5,421
2021	5,421
2022	4,224
Thereafter	342
Total	$	24,895

Accrued Compensation and Benefits—Accrued compensation and benefits consists of the following:



	As of
	July 31, 2017		October 31, 2017
	(in thousands)
Accrued commissions	$	20,388	$	19,410
Accrued vacation	6,286		6,984
Contributions to ESPP withheld	14,371		6,008
Accrued bonus	7,342		5,384
Payroll taxes payable	3,434		6,603
Other	5,700		5,912
Total accrued compensation and benefits	$	57,521	$	50,301

Accrued Expenses and Other Current Liabilities—Accrued expenses and other current liabilities consists of the following:



	As of
	July 31, 2017		October 31, 2017
	(in thousands)
Accrued professional services	$	4,167	$	3,635
Income taxes payable*	3,873		3,929
Other	1,667		1,867
Total accrued expenses and other current liabilities	$	9,707	$	9,431

* Balance as of July 31, 2017 was adjusted to reflect the impact of the adoption of ASC 606 on income taxes. See Note 3 for a summary of adjustments.