3.             Cash, Cash Equivalents and Short-term Investments

Cash, cash equivalents and short-term investments consisted of the following:

Our short-term investments have maturities of less than twelve months and are classified as available-for-sale.

The following tables summarize our available-for-sale securities’ adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category as of January 31 and October 31, 2013.

Our investment policy requires investments to be investment grade, primarily rated “A1” by Standard & Poor’s or “P1” by Moody’s or better for short-term investments, with the objective of minimizing the potential risk of principal loss. In addition, the investment policy limits the amount of credit exposure to any one issuer.

The unrealized losses on our available-for-sale securities as of January 31, 2013 were primarily a result of unfavorable changes in interest rates subsequent to the initial purchase of these securities. As of October 31, 2013, we did not own any securities that were in an unrealized loss position. During the three and nine months ended October 31, 2013, we did not recognize any impairment charges.