Any TUT, or other spread trader for that matter, have issues with account value, when a spread position is on at IB? One minute it's value X, then 1 minute later it's X-$200, even though the B/A doesn't change and no trades print? Is there any underlying spread market that's pricing, rather than the B/A of the ZT & ZN? Is it underlying MM activity changing the B/A vis a vis decimals? Is it fluctuating DV01's that are doing this? What's going on? It's easier to analyze and trade it, then cash it in, for pete's sake.