On 02.01.2014 you create inventory of 1 for 950000 with a cancellation posting.
on 18.03.2014 you got an external receipt of 1 for 1050000.
this makes a total of 2 with a total amount of 2100000, which is an average of 1050000 per 1
All 4 movements from 26.04. to 06.06. are goods issues (and cancellation of goods issue), they are all valuated at moving average as you can calculate yourself.
However this does not really explain the gain/loss financial document for the most recent posting from 06.06.
Such posting can for example occur in case of standard price price valuation where a user enters an external amount in LC.
It can as well occur if the movement brings the stock to zero, since it is not possible to have a remaining value when the stock becomes nil, even quantity * price is unequal to the total value (but here we usually have only smaller amounts due to rounding issues.)
You should analyze whether you had material master changes regarding the price control in 2014. Further it would be helpful for further analysis to see the MR51 list for the same period