I would assume that if you have your SIAF-shares on an account that is not allowed to hold non-european stocks (SIAF-ME being european, SIAF not - and TRW certainly not, as of today at least) they you will have to pay taxes both when the TRW-shares are moved out of that account, and then when you sell (the total taxes being the same, but part of the burden coming earlier). Hence it might be an idea to have your SIAF-shares on an account that allows non-european stocks.
Regarding TRW-shares I have asked Nordnet if they will force-sell TRW-shares (against my will) since Nordnet doesn't allow for stocks traded on HKSE. I asked the same question last year, but they seem unable to give me a straight answer to that question. At least in this case you will have the cash-flow from the same of TRW-shares to cover the tax expenses.
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.