NOTE 4. INVESTMENTS

Our investments generally consist of money market funds, commercial paper and corporate debt securities and municipal bonds. All of our investments have original maturity (maturity at the purchase date) of less than 12 months. Investments with original maturities of three months or less are classified as cash equivalents.

We classify our investments as available-for-sale at the time of purchase and we reevaluate such classification as of each balance sheet date. These short-term investments are carried at fair value with unrealized gains or losses classified as a component of accumulated other comprehensive income (loss). Amortization of premiums and accretion of discounts to maturity are computed under the effective interest method and is included in interest income. Interest on securities is included in interest income when earned. Realized gains and losses on the sale of investments are determined using the specific identification method and recorded in "Other income (expense) in the Condensed Consolidated Statements of Operations and Comprehensive Income (Loss).”

We did not hold investments as of December 31, 2014 and our investments as of June 30, 2015 were as follows (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value/Net Carrying Value		Cash and Cash Equivalents		Investments
Money market funds	$	4,485	$	-	$	-		$	4,485	$	4,485	$	-
Commercial paper		32,481		-		-			32,481		5,999		26,482
Corporate debt securities		35,870		3		(28	)		35,845		1,457		34,387
Municipal bonds		8,748		5		-			8,753		4,971		3,783
		81,584		8		(28	)		81,564		16,912		64,652

At June 30, 2015, we had $28,000 of gross unrealized losses on certain investments. We regularly review our investment portfolio to identify and evaluate investments that have indications of possible impairment that is other-than-temporary. Factors considered in determining whether a loss is temporary include:

•the length of time and extent to which fair value has been lower than the cost basis;

•the financial condition, credit quality and near-term prospects of the investee; and

•whether it is more likely than not that the Company will be required to sell the security prior to recovery.

We believe that there were no investments held at June 30, 2015 that were other-than-temporarily impaired. For the six months ended June 30, 2015, proceeds from sales and maturities of investments were $2.2 million for an immaterial realized gain, $1.2 million of these sales were securities included in cash equivalents.

Interest Expense:

The following table presents the components of interest expense incurred on the Notes and on other borrowings (in thousands):

	Three Months Ended		Six Months Ended
	June 30, 2015		June 30, 2015
2.50% Convertible Notes:
Interest expense at 2.50% coupon rate	$	725	$	725
Amortization of debt discount		921		921
Amortization of deferred debt issuance costs		97		97
Total interest from 2.50% convertible notes		1,743		1,743
Other Borrowings:
Interest from other borrowings		25		459
Total interest	$	1,768	$	2,202

	Three Months Ended		Six Months Ended
	June 30, 2014		June 30, 2014
Other Borrowings:
Interest from other borrowings	$	84	$	195
Total interest	$	84	$	195