[How should FIFO affect the remaining average price?]

I recently asked IG a question about the FIFO netting method they use and how it affects the average price of your remaining position?  Maybe I will have better luck getting a clearer answer from the community.

I have the following example:

2 purchases: 

1st: 8 units @ price 110

2nd: 8 units @ price 100

Therefore average price is 105 for 16 units purchased.

If I sell 4 units at 100, I assume that this sale should be netted against the 1st purchase of 8 units @ price 110, effectively meaning that this purchase is now worth 4 shares @ price 110 and I have realized a loss of of (4 x -10) = -$40 which is reflected in my capital.

My portfolio  should be left with:

1st: 4 units @ price 110 (FIFO nets my sale of 4 units against my first purchase of 8 units @ price 110)

2nd: 8 units @ price 100

Therefore, the average price of the remaining 12 units is now 103.33.

 

I would like the community to let me know if this example is correct?  My issue is that, using the above example, when I sell 4 units in a real-life situation, IG does not adjust the average price of my position in my Portfolio.  IG continue to show my average price as 105. 

[Currency Conversion - Automatic or Manual]

Has anyone here analyzed the cost impact of Automatic versus Manual conversion selection when buying shares dominated in a foreign currency?

 

Would appreciate it if someone with some knowledge on the subject could shed light on whether it is more beneficial to the trader to chose one option above the other.

 

Thanks in advance 

[How to create an API for Excel that will show my Account Live Profit or Loss]

Is there anyone in the community who can help me create an API that will allow me to see my Accounts Profit or Loss in Excel?  I have tried to understand the information that IG has published on the subject but it's not very clear to me.  I'm hoping someone can explain it to me by specifically focusing on answering my question.  Many Thanks