5. CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Cash, cash equivalents and short-term investments consist of the following (in thousands):

 

 

Cash equivalents and short-term investments included the following securities with gross unrealized gains and losses (in thousands):

 

 

 

 

 

 

As of December 31, 2016, our cash equivalents and short-term investments, which have contractual maturities within one year, had a weighted‑average time to maturity of approximately 91 days. We view our short-term investments portfolio as available for use in current operations.  We have the ability to hold all investments as of December 31, 2016 through their respective maturity dates. At December 31, 2016, we had no investments that had been in a continuous unrealized loss position for more than 12 months. As of December 31, 2016, a total of 27 individual securities had been in an unrealized loss position for 12 months or less and the losses were deemed to be temporary. The gross unrealized losses above were caused by interest rate increases. No significant facts or circumstances have arisen to indicate that there has been any deterioration in the creditworthiness of the issuers of the securities held by us. Based on our review of these securities, including the assessment of the duration and severity of the unrealized losses and our ability and intent to hold the investments until maturity, there were no other-than-temporary impairments for these securities at December 31, 2016.

 

The following table shows the fair value and gross unrealized losses of our investments in individual securities that are in an unrealized loss position, aggregated by investment category (in thousands):