FAIR VALUE

As of June 30, 2015 and December 31, 2014, financial assets (excluding cash balances) measured at fair value on a recurring basis as described in Note 1, "Summary of Significant Accounting Policies," are summarized as follows (in thousands):



	As of June 30, 2015						As of December 31, 2014
	Fair Value Measurement Using						Fair Value Measurement Using
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
Money market funds	$	258	$	—	$	258	$	733	$	—	$	733
Total cash equivalents	258		—		258		733		—		733
Commercial paper and corporate bonds	—		414,551		414,551		—		417,126		417,126
U.S. government agency debt securities	—		14,500		14,500		—		—		—
Total marketable securities	—		429,051		429,051		—		417,126		417,126
Total financial assets	$	258	$	429,051	$	429,309	$	733	$	417,126	$	417,859

As of June 30, 2015 and December 31, 2014, the Company had no financial liabilities measured at fair value on a recurring basis, and none of its financial assets measured at fair value on a recurring basis relied upon Level 3 inputs.

Investments in money market funds have been classified as Level 1 since these securities are valued based upon $1.00 net asset value per share or unadjusted quoted prices in active markets. Investments in commercial paper, corporate bonds, and U.S. government agency debt securities have been classified as Level 2 as they are valued using quoted prices in less active markets or other directly or indirectly observable inputs. Fair values of corporate bonds and U.S. government agency debt securities were derived from a consensus or weighted-average price based on input of market prices from multiple sources at each reporting period. With regard to commercial paper, all of the securities had high credit ratings and one year or less to maturity; therefore, fair value was derived from accretion of purchase price to face value over the term of maturity or quoted prices for similar instruments if available. During the six months ended June 30, 2015 and 2014, there were no transfers of financial assets between Level 1 and Level 2.

The carrying amounts of all other current financial assets and current financial liabilities reflected in the consolidated balance sheets approximate fair value due to their short-term nature.