Is it normal for markets to close from 17:00-17:15 est? Or is this something only IB does? Today, I was up 40 pips at 17:00 and all my quotes dissappeared. The quotes came back at 17:15 and I was -10 pips.
5pm EST rollover is pretty much the standard. Depending on the platform, you'll either get logged off or the prices will freeze for a couple minutes. This is when you are credited/debited rollover interest for any open positions.