I still don't get it. Suppose you are spreading YM/ES. So, you are long YM and short the equivalent dollar amount of ES. You can still add/reduce both positions in accordance with your "averaging up" strategy. Now, what prevents you from doing in a single account? What's the need for two accounts?
It works both ways. It's just the impact of the US markets on the global markets may be larger due to the size, so the US->Japan correlation is more noticible than the opposite correlation.
I would program and test it for you, but the method needs to be defined more clearly. As someone already noted, there is no indication of how the "trend" and the trend "reversal" are identified.
JSystemTrader version 6.04 is now available:
http://www.myjavaserver.com/~nonlinear/JSystemTrader/JSystemTrader.html
There are substantial changes in this release:
API-9.0.jar has been superceeded by API-9.2.jar. JSystemTrader now uses the latest production version of the IB API...