Offshore equity stocks and ETF held for ST trading purposes

I had been trading equity stocks and ETF in the US and other places outside UK for years before I became a UK tax resident during the tax year 2021-22. The trading gains were not subject to any foreign taxes. 1. Should I report the net gain/loss as trading income or capital gains? Which form should I use? 2. Funds for trading were kept with the brokers in the original currencies well before I became a UK tax resident, and withdrawal were not made with reference to any specific transaction nor were they converted to GBP. Which exchange rate should I use to translate the realised gain and loss? Thanks.

Hi,
 

Any gains arising prior to 21/22 would not be taxable in the UK.  Any gains prior prior to 21/22, remitted to the UK during or after 21/22 would be considered captial and not be taxable.  Any foreign gains arising during 21/22 would be taxable, depending on your residence status.  Have a look at : Tax on foreign income     and    : Guidance note for residence, domicile and the remittance basis: RDR1  .  The official exchange rates can be found at : Exchange rates from HMRC in CSV and XML format   . Thank you.