Hedging currency exposure for cross-border portfolios

Holding foreign assets means holding an implicit currency position, whether you intended to or not. A portfolio of US equities purchased in euros is exposed to the euro-dollar exchange rate just as surely as it is exposed to the S&P 500. Ignoring that exposure does not make it disappear; it simply leaves returns to chance.

This note walks through hedge ratios, rollover costs, and the cases where leaving exposure unhedged is the cheaper decision. A full hedge removes currency risk but also removes currency upside. A partial hedge keeps some participation while reducing volatility. The right ratio depends on the investor's view, time horizon, and tolerance for double-digit swings.

Rollover costs matter more than many realise. Forward points and funding charges accumulate over months and years. A hedge that looks cheap today can become expensive if held through multiple rollovers. We encourage clients to model the total cost over the intended holding period rather than focusing only on the entry spread.

There are also cases where hedging is not worth the complexity. A small, long-term position in a stable currency pair may not justify the operational overhead. A trader with a strong directional view on the underlying asset may prefer to accept currency noise rather than pay away potential alpha.

The decision framework is simple: quantify the exposure, estimate the cost to hedge, compare it to the expected volatility of the exposure, and decide whether the protection is worth the price. When the numbers are close, we usually favour simplicity. A slightly imperfect hedge that is actually maintained beats a theoretically perfect hedge that is abandoned after the first rollover.