Hi jcl. This thread sidetracked into a DD vs. NDD discussion, but I'd like to return to the original reTraining focus and clear up my remaining misunderstandings.

a) I understand the point that correct History needs to be in place for the reTraining to be good. In terms of my VPS, that seems from what I experienced to mean that a vanilla install isn't good enough, especially if the install happens in 1 year and the reTrain happens in the next year. (I.e., my reTrain successfully downloaded 2016 prices but failed trying to download 2015 prices.) It seems the solution to this History concern is to add a step before reTraining: Download and install (reinstall if updated) all Zorro History zip's (and any other history) needed by the strategy. This would ensure that all available History is present (to be "topped off" by the reTrain); and also that the latest History is available incorporating any fixes for errors that have been discovered. Does this process make sense to you?

b) I'm still having trouble wrapping my head around broker's costs differences not mattering to reTraining. It seems to me that different costs would lead to different trades and hence to different optimizations = different parameters. A specific question from my situation: I develop on one machine & Trade on a VPS, on which I've only done a vanilla install, and updated History (per above ). My development machine has my AssetsFix.csv. The VPS has your vanilla AssetsFix.csv. If I reTrain on the VPS, it will use your AssetsFix.csv - is this correct/OK?

c) If the only thing needed from the broker connection for reTraining is "topping off" History, then reTraining can be done anytime - like, say, Sunday as soon as the broker comes back up - correct?

Thanks!