I see almost on a daily basis an algorithm that is usually active around 2pm CST that keeps buying/selling a fixed number of lots in treasury futures at what seems like fixed time intervals. It can be seen on cumulative delta chart (you have to go down to one second resolution). Attached pictures shows cumulative delta for UBM2 (ultrabond June 12 futures contract) on 4/4/2012. It's so obvious that it almost seems the algo 'wants to' be seen. Sometimes (not always) there is simultaneous selling of another treasury futures contract (for example buying ZN and selling ZB, so probably playing the spread). Was wondering if someone else (most likely technically savvy...) noticed this too? Maybe there is something to exploit here (by following the algo). Feel free to pm me to discuss my/your observations.