| Fair Value, Assets Measured on Recurring Basis |
The following tables present information about our assets that are measured at fair value on a recurring basis using the above input categories (in thousands): | | | | | | | | | | | | | | Level 1 | | Level 2 | | Total | December 31, 2015 | | | | | | Cash equivalents: | | | | | | Money market mutual funds | $ | 1,038 |
| | $ | — |
| | $ | 1,038 |
| U.S. agency obligations | — |
| | 3,000 |
| | 3,000 |
| Marketable securities: | | | | | | U.S. agency obligations | — |
| | 80,715 |
| | 80,715 |
| U.S. treasury securities | — |
| | 33,893 |
| | 33,893 |
| | $ | 1,038 |
|
| $ | 117,608 |
|
| $ | 118,646 |
|
| | | | | | | | | | | | | | Level 1 | | Level 2 | | Total | December 31, 2014 | | | | | | Cash equivalents: | | | | | | Money market mutual funds | $ | 1,919 |
| | $ | — |
| | $ | 1,919 |
| U.S. agency obligations | — |
| | 1,561 |
| | 1,561 |
| Marketable securities: | | | | | | U.S. agency obligations | — |
| | 175,696 |
| | 175,696 |
| U.S. treasury securities | — |
| | 5,581 |
| | 5,581 |
| | $ | 1,919 |
|
| $ | 182,838 |
|
| $ | 184,757 |
|
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