To track changes of moving average price in SAP (Stock card and inventory report):
T Code: S_P00 _07000139
Enter input data in the screen (selection criteria) viz.,
date
........ etc
and the execute (F8)
Now you can observe material quantity, price per unit, total quantity with respect to movement type (receipt / issue).
By analyzing these you can understand how the moving average price is being updated in moving average price column.