have you checked out the nadex, also a guy in the dfw area holds webinars on this, find it on yorba radio on the web or radio 1190 am in dfw http://www.nadex.com/markets-to-trade.html
Thanks for the reply. I did check on Nadex but I don't believe they offer a 15 min. expiry time. I'm looking to trade on 15 minutes and looking for a broker who offers that. If someone who has been using a broker offering that and is reliable, I would be happy to hear from you. Thanks