I'm aware that gains from investing is liable to capital gains tax. I'm also aware that income from trading is liable to income tax. I'm not asking what counts as trading and what as investing. My question is, what happens at the threhsold between the two?
Consider: I bought 1 bitcoin ages ago for £100. Today it is worth £10k, and I deposit it as collateral on an exchange and open a leverage long position. A month later, when bitcoin is worth £20k, I close the position and get my original 1 bitcoin back and £10k GBP profit.
Obviously, the £10k GBP I received counts as income from a tax perspective. But, what about the bitcoin? Does this count as a 'sale' @£10k for capital gains purposes when I opened the position? And does it count as a purchase when I close the position, this time @£20k? Or perhaps there is neither a sale nor purchase from a capital gains perspective, it is like I held onto it the entire time?