Note 2. Investments and Fair Value Measurements

Our cash, cash equivalents and investments are classified as follows (in thousands):

	March 31, 2014									December 31, 2013
			Gross		Gross							Gross		Gross
	Amortized		Unrealized		Unrealized			Fair		Amortized		Unrealized		Unrealized			Fair
	Cost		Gain		(Loss)			Value		Cost		Gain		(Loss)			Value
Classified as:
Cash	$	21,638	$	—	$	—		$	21,638	$	24,852	$	—	$	—		$	24,852
Cash equivalents:
Money market fund		1,122		—		—			1,122		109		—		—			109
Total cash and cash equivalents		22,760		—		—			22,760		24,961		—		—			24,961

Investments (available for sale):
Certificates of deposit		7,864		1		(2	)		7,863		6,320		2		(4	)		6,318
Corporate bonds		14,155		12		(2	)		14,165		14,276		8		(6	)		14,278
Corporate equity security		125		1,900		—			2,025		125		1.923		—			2,048
Total investments		22,144		1,913		(4	)		24,053		20,721		1,933		(10	)		22,644
Total cash, cash equivalents and investments	$	44,904	$	1,913	$	(4	)	$	46,813	$	45,682	$	1,933	$	(10	)	$	47,605
Contractual maturities on investments:
Due within 1 year	$	20,464						$	22,375	$	10,569						$	12,499
Due after 1 through 5 years		1,680							1,678		10,152							10,145
	$	22,144						$	24,053	$	20,721						$	22,644

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. There were no sales of available-for-sales securities and no realized gains and losses for the three months ended March 31, 2014 and 2013.

Also included in short-term investments at March 31, 2014 is our investment in the common stock of Intelligent Epitaxy Technology, Inc (IntelliEPI), a Taiwan publicly-traded company. We began classifying this asset as an available-for- sale security upon its initial public offering (IPO) in 2013. Prior to the IPO in 2013, we sold some of our stock in IntelliEPI and realized a gain of approximately $800,000. An unrealized gain of $1.6 million net of tax was recorded as of March 31, 2014. These securities are valued at fair market value at March 31, 2014. There is no assurance that the Company will realize this value when the securities are sold in the future.

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 March 31, 2014 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.

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 March 31, 2014 (in thousands):

	In Loss Position < 12 months									In Loss Position > 12 months									Total In Loss Position
					Gross										Gross							Gross
	Fair				Unrealized					Fair					Unrealized				Fair			Unrealized
	Value				(Loss)					Value					(Loss)				Value			(Loss)
Investments:
Certificates of deposit			$	1,918			$	(1	)			$	1,239			$	(1	)		$	3,157		$	(2	)
Corporate bonds		—		—		2,382		(2	)		2,382		(2	)
Total in loss position			$	1,918			$	(1	)			$	3,621			$	(3	)		$	5,539		$	(4	)

	In Loss Position < 12 months										In Loss Position > 12 months									Total In Loss Position
						Gross										Gross							Gross
	Fair					Unrealized					Fair					Unrealized				Fair			Unrealized
	Value					(Loss)					Value					(Loss)				Value			(Loss)
Investments:
Certificates of deposit			$	3,425				$	(4	)			$	720			$	(0	)		$	4,145		$	(4	)
Corporate bonds		4,473		(5	)		3,711		(1	)		8,184		(6	)
Total in loss position			$	7,898				$	(9	)			$	4,431			$	(1	)		$	12,329		$	(10	)

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 these companies, including minority investments indirectly in privately-held companies made by our consolidated joint ventures, accounted for under the equity method are included in "other assets" in the consolidated balance sheets and totaled $11.0 million and $10.9 million as of March 31, 2014 and December 31, 2013, respectively.

We also maintain minority investments in one company which is accounted for under the cost method as we do not have the ability to exercise significant influence over their operations. Our investments under the cost method are reviewed for other than temporary declines in value on a quarterly basis. We monitor our investments for impairment and record reductions in carrying value when events or changes in circumstances indicate that the carrying value may not be recoverable. As of March 31, 2014 and December 31, 2013, our investments in this unconsolidated company had a carrying value of $200,000 and were also included in "other assets" in the condensed consolidated balance sheets.

Fair Value Measurements

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 involving identical assets. Level 2 instrument valuations are obtained from readily-available 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. As of March 31, 2014, we did not have any Level 3 assets or liabilities. 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, 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 quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. There were no changes in valuation techniques or related inputs in the three months ended March 31, 2014. There have been no transfers between fair value measurement levels during the three months ended March 31, 2014.

The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of March 31, 2014 (in thousands):

	Balance as of March 31, 2014		Quoted Prices in Active Markets of Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents and investments:
Money market fund	$	1,122	$	1,122	$	—
Certificates of deposit		7,863		—		7,863
Corporate bonds		14,165		—		14,165
Corporate equity securities		2,025		2,025		—
Total	$	25,175	$	3,147	$	22,028
Liabilities	$	—	$	—	$	—

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, 2013 (in thousands):

	Balance as of December 31, 2013		Quoted Prices in Active Markets of Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents and investments:
Money market fund	$	109	$	109	$	—
Certificates of deposit		6,318		—		6,318
Corporate bonds		14,278		—		14,278
Corporate equity securities		2,048		2,048		—
Total	$	22,753	$	2,157	$	20,596
Liabilities	$	—	$	—	$	—

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 either of these investments during the three months ended March 31, 2014 or 2013.