Note 2. Cash, Cash Equivalents and Investments

Our cash and cash equivalents consist of cash and instruments with original maturities of less than three months. Our investments consist of instruments with original maturities of more than three months. As of December 31, 2016 and 2015, our cash, cash equivalents and investments are classified as follows (in thousands):


	December 31, 2016								December 31, 2015
			Gross		Gross						Gross		Gross
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
	Cost		Gain		(Loss)		Value		Cost		Gain		(Loss)		Value
Classified as:
Cash	$	23,948	$	—	$	—	$	23,948	$	10,289	$	—	$	—	$	10,289
Cash equivalents:
Certificates of deposit 1		12,204		—		—		12,204		14,586		—		—		14,586
Total cash and cash equivalents		36,152		—		—		36,152		24,875		—		—		24,875
Investments (available for sale):
Certificates of deposit 2		8,999		1		(20)		8,980		9,795		1		(13)		9,783
Corporate bonds		8,479		—		(47)		8,432		8,776		—		(63)		8,713
Corporate equity securities		48		111		—		159		200		432		—		632
Total investments		17,526		112		(67)		17,571		18,771		433		(76)		19,128
Total cash, cash equivalents and investments	$	53,678	$	112	$	(67)	$	53,723	$	43,646	$	433	$	(76)	$	44,003
Contractual maturities on investments:
Due within 1 year	$	11,325					$	11,415	$	11,022					$	11,437
Due after 1 through 5 years		6,201						6,156		7,749						7,691
	$	17,526					$	17,571	$	18,771					$	19,128

Certificate of deposit with original maturities of less than three months.

Certificate of deposit with original maturities of more than three months.

We manage our investments as a single portfolio of highly marketable securities that is intended to be available to meet our current cash requirements. We have no investments in auction rate securities. Certificates of deposit and corporate bonds are typically held until maturity. Corporate equity securities have no maturity and may be sold at any time. Our holding of corporate equity securities consists of common stock of GCS Holdings, Inc. (“GHI”) (previously Global Communication Semiconductors, Inc), a Taiwan publicly-traded company. Previously, we also owned the common stock of Intelligent Epitaxy Technology, Inc. (“IntelliEpi”). We began classifying IntelliEpi stock as an available-for-sale security upon its initial public offering in 2013 and sold our remaining IntelliEpi stock in the second quarter of 2015 and we no longer hold any IntelliEpi stock as of December 31, 2016. In 2015, our cash proceeds from sales of IntelliEpi stock, an available-for-sale investment, were $902,000, our cost was $43,000 and our gross realized gain was $859,000. In 2014, our cash proceeds from sales of this available-for-sale investment were $1.3 million, our cost was $82,000 and our gross realized gain was $1.3 million.

We began classifying GHI as an available-for-sale security in the second quarter of 2015 when we determined that there was sufficient trading volume in the exchange for the stock to be deemed readily marketable. An unrealized gain of $111,000 and $432,000, net of tax, was recorded as of December 31, 2016 and 2015, respectively. This security is valued at fair market value at December 31, 2016 and will be marked to market with changes through other comprehensive income until sold. There is no assurance that we will realize this value when the stock is sold in the future. In 2016, we sold some of our GHI stock and our cash proceeds from sales of this available-for-sale investment was $581,000. Our cost was $152,000 and our gross realized gain from sales of this available-for-sale investment was $429,000. There were no sales of GHI stock for the year ended December 31, 2015.

The gross unrealized losses related to our portfolio of available-for-sale securities were primarily due to changes in interest rates and market and credit conditions of the underlying securities. We have determined that the gross unrealized losses on some of our available-for-sale securities as of December 31, 2016 are temporary in nature. We periodically review our investment portfolio to identify and evaluate investments that have indications of possible impairment. Factors considered in determining whether a loss is temporary include the magnitude of the decline in market value, the length of time the market value has been below cost (or adjusted cost), credit quality, and our ability and intent to hold the securities for a period of time sufficient to allow for any anticipated recovery in market value.

A portion of our investments would generate a loss if we sold them on December 31, 2016. The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2016 (in thousands):


	In Loss Position				In Loss Position				Total In
	< 12 months				> 12 months				Loss Position
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
As of December 31, 2016	Value		(Losses)		Value		(Losses)		Value		(Losses)
Investments:
Certificates of deposit	$	5,211	$	(20)	$	1,200	$	—	$	6,411	$	(20)
Corporate bonds		5,037		(35)		3,395		(12)		8,432		(47)
Total in loss position	$	10,248	$	(55)	$	4,595	$	(12)	$	14,843	$	(67)

The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2015 (in thousands):


	In Loss Position				In Loss Position				Total In
	< 12 months				> 12 months				Loss Position
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
As of December 31, 2015	Value		(Loss)		Value		(Loss)		Value		(Loss)
Investments:
Certificates of deposit	$	4,509	$	(11)	$	3,543	$	(2)	$	8,052	$	(13)
Corporate bonds		6,866		(56)		1,847		(7)		8,713		(63)
Total in loss position	$	11,375	$	(67)	$	5,390	$	(9)	$	16,765	$	(76)

Investments in Privately-held Companies

We have made strategic investments in private companies located in China in order to gain access at a competitive cost to raw materials that are critical to our substrate business (see Note 6). The investment balances for all of these companies, including minority investments indirectly in privately-held companies made by our consolidated subsidiaries accounted for under the equity method, are included in “other assets” in the consolidated balance sheets and totaled $11.3 million and $13.7 million as of December 31, 2016 and December 31, 2015, respectively. As of December 31, 2016, there were seven companies accounted for under the equity method.

As noted above, in the second quarter of 2015, we re-classified our minority investment in GHI, which was accounted for under the cost method, as an available-for- sale security and valued the security at fair market value. As of December 31, 2016 and 2015, we no longer maintain any investments under the cost method. As of December 31, 2014, our investments in this unconsolidated company had a carrying value of $200,000 and were also included in “other assets” in the consolidated balance sheets.

Fair Value Measurements

We invest primarily in money market accounts, certificates of deposits, corporate bonds and notes, and government securities. ASC topic 820, Fair value measurement (“ASC 820”) establishes three levels of inputs that may be used to measure fair value. Level 1 instrument valuations are obtained from real-time quotes for transactions in active exchange markets of the asset or identical assets. Level 2 instrument valuations are obtained from readily-available, observable pricing sources for comparable instruments. Level 3 instrument valuations are obtained from unobservable inputs in which there is little or no market data, which require us to develop our own assumptions. On a recurring basis, we measure certain financial assets and liabilities at fair value, primarily consisting of our short-term and long-term investments.

The type of instrument valued based on quoted market prices in active markets include our money market funds, which are generally classified within Level 1 of the fair value hierarchy. Other than corporate equity securities which are based on quoted market prices and classified as Level 1, we classify our available-for-sale securities including certificates of deposit and corporate bonds as having Level 2 inputs. The valuation techniques used to measure the fair value of these financial instruments having Level 2 inputs were derived from bank statements, quoted market prices, broker or dealer statements or quotations, or alternative pricing sources with reasonable levels of price transparency. There were no changes in valuation techniques or related inputs in the year ended December 31, 2016. There have been no transfers between fair value measurement levels during the year ended December 31, 2016.

We place short-term foreign currency hedges that are intended to offset the potential cash exposure related to fluctuations in the exchange rate between the United States dollar and Japanese yen. We measure the fair value of these foreign currency hedges at each month end and quarter end using current exchange rates and in accordance with generally accepted accounting principles. At quarter end any foreign currency hedges not settled are netted in “accrued liabilities” on the consolidated balance sheet and classified as Level 3 assets and liabilities. As of December 31, 2016, the net change in fair value from the placement of the hedge to settlement at each month end during the quarter had a de minimis impact to the consolidated results.

The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of December 31, 2016 (in thousands):


			Quoted Prices in				Significant
			Active Markets of		Significant Other		Unobservable
	Balance as of		Identical Assets		Observable Inputs		Inputs
	December 31, 2016		(Level 1)		(Level 2)		(Level 3)
Assets:
Cash equivalents and investments:
Certificates of deposit	$	21,184	$	—	$	21,184	$	—
Corporate bonds		8,432		—		8,432		—
Corporate equity securities		159		159		—		—
Total	$	29,775	$	159	$	29,616	$	—

The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of December 31, 2015 (in thousands):


			Quoted Prices in				Significant
			Active Markets of		Significant Other		Unobservable
	Balance as of		Identical Assets		Observable Inputs		Inputs
	December 31, 2015		(Level 1)		(Level 2)		(Level 3)
Assets:
Cash equivalents and investments:
Certificates of deposit	$	24,369	$	—	$	24,369	$	—
Corporate bonds		8,713		—		8,713		—
Corporate equity securities		632		632		—		—
Total	$	33,714	$	632	$	33,082	$	—

Items Measured at Fair Value on a Nonrecurring Basis

Certain assets that are subject to nonrecurring fair value measurements are not included in the table above. These assets include investments in privately-held companies accounted for by equity and cost method (See Note 6). We did not record other-than-temporary impairment charges for these investments during 2016.