This is just stupid. I doubt anyone cares about his personal finances unless he was making his money selling drugs, children or arms to terrorists. Plenty of people own stocks in foreing companies. It just good risk diversification.
The extreme example of avoiding even the appearance of a conflict of interest is Alan Greenspan, who keeps all of his personal financial assets in T-bills, by definition earning the least interest possible, and having no opportunity to speculate in stocks.
The polar opposite is DiFi, who sits on the Senate Foreign Affairs ctte, and whose husband is palsy with the chicoms.