This was talked about recently and Mark Wagner explains it here:
In brief, the Stock Status report can be run for previous days but only for the part quantities. The costs on the report are whatever they are at the time the report runs using the part’s costing type (Standard, Average, etc.). I’ll be corrected if I’m wrong but that seemed to be the consensus.
It’s been recommended to do a snapshot of your PartCost table nightly so that you could do some revaluation if necessary in Excel.
The stock status report takes the current cost method of the part in part
maintenance (avg, std, etc) and multiplies it times the quantity on hand at
the date the report is run. There is a checkbox where you can override that
and have Epicor calculate the weighted average cost