purchases of equity securities by the issuer on 15 september 2011 , the board of directors authorized the repurchase of up to $ 1.0 billion of our outstanding common stock . this program does not have a stated expiration date . we repurchase shares pursuant to rules 10b5-1 and 10b-18 under the securities exchange act of 1934 , as amended , through repurchase agreements established with one or more brokers . there were no purchases of stock during fiscal year 2018 . at 30 september 2018 , $ 485