Taxing unrealized gains is bonkers. But accruing tax on unrealized gains makes a lot of sense. I built Monzo when I lived in the UK and accrued a lot of (paper) gains during that time. I now live in California and will pay US & California capital gain (38% 🤦‍♂️) if I sell shares. But I won’t pay anything in the UK. If Nik from Revolut sells shares as a Dubai tax resident, he will pay 0% capital gains. I feel like we both benefited enormously from the UK and we have a duty to give back. Entrepreneurs should be required to keep a record of their tax residence and the fair market value of their shareholding each year, and then pay capital gains proportionately when they sell. The US solves this by taxing their citizens’ worldwide income, regardless of residence. (source)