We looked at the total taxes Mr Rogan would pay if he sold before or after the deadline.
Since he purchased the US mutual funds, they had risen in value by over $500,000, so if Mr Rogan sold before the deadline, the US Capital Gains Tax (CGT) and Net Investment Income Tax (NIIT) would total $119,000. However, if he delayed the sale until a future year after the deadline, he would instead need to pay 45% UK income tax when they were sold, as well as 3.8% NIIT. This would have resulted in a global tax bill of around $317,125, after taking exchange rates and foreign tax credits into consideration.
By pointing this out, Mr Rogan decided to sell early and saved around $198,125, simply by proactive planning. If he had left the sales until later tax years, he would have paid 63% of US dollar gains as tax!