In order to more closely control the number of contracts being traded and to prevent unauthorized use, TradingVisions may at any time limit or end the purchase of system licensing. Through September 30, 2009, limited licensing is available. Additionally, in general, TradingVisions restricts the purchase of system licensing to US citizens, with individual exceptions sometimes made on a case-by-case basis. If you are a non-US citizen and would like to purchase or be put on a waiting list to purchase, please contact TradingVisions at systems@tradingvisions.com. 