But the story evolved over the course of the year. As the chart shows, the investment journey for sterling-denominated investors looked very different from that experienced by domestic investors.
In the first quarter, sterling rallied against the dollar, breaching $1.40 to the pound in April. That is reflected in the chart above, with sterling-denominated investors lagging in the early part of the year.
As 2018 progressed and Brexit-fuelled concerns took hold, the pound fell sharply against the dollar.
This manifests itself in the surge in the orange line from around June onwards.
And although all investors in the US suffered a reversal through the latter third of the year, currency effects mean sterling investors still registered a small gain over the year.
These are exactly the same assets, and while there are multiple factors impacting on the performance of the shares in the index, the divergence of UK and US investors is accounted for through the impact of the currency translation.
Sitting tight
Turning once again to the UK, Brexit continues to dominate the news agenda. Data from the Investment Association shows that UK savers have been reluctant to put money into investment funds over the past year, with many commentators attributing that nervousness to worries about Brexit.
We have already explored the make-up of the UK stock market and recognised that Brexit-related currency weakness can mean different things for firms in the index, depending on where they buy and sell their goods and services.
Nonetheless, it probably is not surprising that for many people their natural inclination is to sit tight amid the current uncertainty, or for them to favour non-UK assets.
But it is important for investors to recognise that even those who opt to reduce their exposure to UK holdings will still find that the impact of related currency movements still affects them.
For argument's sake, let us imagine that the EU and UK can agree a measured Brexit plan that is received by the markets in positive terms, and as a result the pound were to rally and gain 10 per cent against other currencies.
Sterling investors would (assuming no changes in the underlying asset prices) automatically see 10 per cent shaved off their euro and dollar investment holdings.
Even an investor that had cut their UK exposure would still be affected by Brexit-related matters.
And once again, the impact would likely feel counterintuitive to many customers as a reported strengthening in the outlook for the UK economy perversely sees them incur paper losses in their portfolio.
Managing currency movements
This examination of currency effects on global assets gives us a sense of how sensitive portfolios can be to movements in exchange rates.
