NOTE S—Selected Quarterly Financial Data (unaudited)

The following tables set forth a summary of the Company’s quarterly financial information for each of the four quarters for the years ended December 31, 2017 and 2016 (in thousands, except per share data):


	First		Second		Third		Fourth
Year ended December 31, 2017	Quarter		Quarter		Quarter		Quarter

Revenue	$	96,224	$	117,371	$	88,879	$	79,855
Cost of goods sold		54,752		64,089		49,507		47,701
Gross profit		41,472		53,282		39,372		32,154
Gross margin		43.1%		45.4%		44.3%		40.3%

Operating expenses:
Research and development		7,432		8,073		9,190		10,670
Sales and marketing		1,903		2,158		2,551		2,090
General and administrative		7,822		8,786		9,580		9,074
Total operating expenses		17,157		19,017		21,321		21,834

Income from operations		24,315		34,265		18,051		10,320
Interest and other income (expense), net		(872)		(111)		(541)		(901)
Net income before taxes		23,443		34,154		17,510		9,419
Income tax (expense) benefit		(3,654)		(5,083)		1,865		(3,703)
Net income	$	19,789	$	29,071	$	19,375	$	5,716

Net income per share—basic	$	1.06	$	1.52	$	1.00	$	0.29
Net income per share—diluted	$	1.00	$	1.43	$	0.95	$	0.28


	First		Second		Third		Fourth
Year ended December 31, 2016	Quarter		Quarter		Quarter		Quarter

Revenue	$	50,422	$	55,254	$	70,137	$	84,900
Cost of goods sold		36,169		37,952		46,976		52,662
Gross profit		14,253		17,302		23,161		32,238
Gross margin		28.3%		31.3%		33.0%		38.0%

Operating expenses:
Research and development		8,396		7,814		8,362		7,208
Sales and marketing		1,680		1,610		1,594		1,743
General and administrative		5,733		5,906		6,445		7,443
Total operating expenses		15,809		15,330		16,401		16,394

Income (loss) from operations		(1,556)		1,972		6,760		15,844
Interest and other income (expense), net		34		(1,317)		(356)		(378)
Net income (loss) before taxes		(1,522)		655		6,404		15,466
Income tax (expense) benefit		192		(52)		11,332		(1,241)
Net income (loss)	$	(1,330)	$	603	$	17,736	$	14,225

Net income (loss) per share—basic	$	(0.08)	$	0.04	$	1.03	$	0.81
Net income (loss) per share—diluted	$	(0.08)	$	0.03	$	0.97	$	0.77