Foreign Exchange Earnings and Outgo

It depends upon the instrument that your trading. Follow sheduled accounts and see the format there. Check out fairvalue inveatments standard in as

Forgor to mention, when you buy an instrument its

Investment account dr

To Bank cr. 

But if this is the sales operations then, 

Then as well you have to use the same entry because purchasing is trading activity and inventory compensates for it. Here there is no inventory. Once RECOGNITION is over, gains and losses are taken to income statement. 

So there is no need to rwport it as opex or capex but just the below

(a) the amount of exchange differences included in the net profit
or loss for the period; and
(b) net exchange differences accumulated in foreign currency
translation reserve as a separate component of shareholders’
funds, and a reconciliation of the amount of such exchange
differences at the beginning and end of the period.

Dr. Purchased investments

Cr. Bank

And 

Dr. Inventory

Cr. Trading account

And 

Dr. Bank

Dr. Loss

Cr. Sales

Cr. Gain

And this is because ive gone through cryptocurrency accoubting and it is similar to the above. Inventory must be re ognised as its held for ordinary course of business. 

So from the above an capex purchase will be like 

Dr. Investments

Cr. Bank

But this is not the case here. So just use amounts and no need to classify further as capex or opex on your disclosures. 

Not instrument, actual import

Ok im not familiar with international dtaa and commodiry trading expenses. Opex here in india will be your day to day operating costs and capex is only when imports done for expanding PPE.