Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net income	$ 6,062	$ 13,915
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	1,615	1,448
Deferred income taxes	582	2,451
Stock-based compensation expense	1,672	1,132
Provision for excess and obsolete inventory	607	485
Changes in operating assets & liabilities:
Accounts receivable	7,642	16
Inventories	(6,171)	(11,462)
Prepaid expenses and other current assets	(1,174)	592
Accounts payable and other current liabilities	(16,911)	(1,836)
Deferred revenue	(2,098)	1,963
Income taxes	32	113
Other assets and liabilities	(4,207)	(317)
Net cash (used in) provided by operating activities	(12,349)	8,500
Cash flows from investing activities
Expenditures for property, plant and equipment and capitalized software	(4,255)	(723)
Net cash used in investing activities	(4,255)	(723)
Cash flows from financing activities
Net settlement on restricted stock grants	(281)	(226)
Proceeds from exercise of stock options	1,828	446
Net cash provided by financing activities	1,547	220
Effect of exchange rate changes on cash and cash equivalents	123	(406)
Net (decrease) increase in cash, cash equivalents and restricted cash	(14,934)	7,591
Cash, cash equivalents and restricted cash at beginning of period	184,902	140,880
Cash, cash equivalents and restricted cash at end of period	$ 169,968	$ 148,471

The net cash out flow on net settlement of restricted stock grants.

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