CGT on Crypto disposal

I purchased bitcoin and sold it later for some profit. Instead of selling it back for GBP, I sold it for USDT, a stable cryptocurrency coin. I understand I have to pay for the capital gain tax for the profit in GBP value at the time I sold the bitcoin. Afterwards, I sent the USDT I got from this bitcoin-USDT transaction to my brother. By HMRC’s definition, it is a disposal of asset. Do I have to pay for another CGT for this transfer even the USDT I hold hasn’t gone up in value in GBP term?

Hi,
You will need to convert your USDT rate to pounds sterling to work out your gain.  
If the USDT did not increase in value from the date you acquired it to the date you disposed of it, no capital gain arises.
Thank you.