CGT on Buying US Shares Using USD Balance on Margin Brokerage Account

Hi, At the beginning of 2023/24 tax year I had a positive USD balance (e.g., $10,000) on my margin brokerage account. Not an ISA. During the tax year I used all that balance to buy US shares traded in USD. From HMRC perspective are these BUY transactions treated as a disposal of USD assets, and are they a subject to capital gains tax? Thank you!

Hi,
No, it will only be a disposal if you sell any of the shares.
Thank you.