Hello, everyone. I have been observing the price action of /ZN (10 year Tnote) or /ZB (30 year Tbond) since the beginning of this year. As a newbie, I am very thankful for an explanation for the price gap down happened in Feb 2011. On Feb 20 , 2011 (Sunday), both /ZN and /ZB opened down significantly (I assume on the electronic platform since it happen on Sunday night), compared to their close price on Feb 18, 2011 (Friday). They gradually worked their way up for the entire week on very light volume compared to average. For the next weekend, no gap down happned and their volume was back to normal. Can anyone shed the light on what event caused (if any) the gap down over the weekend? Why is the trading volume so low for this week (the week of Feb 20)? Thank you very much for anyone's insightful reply.