Currency-Hedged vs Unhedged
Currency-Hedged vs Unhedged
Currency hedging in international bond portfolios eliminates FX volatility but has a cost embedded in forward exchange rates; the decision hinges on whether the hedging cost is worth the peace of mind and reduced volatility.
Key takeaways
- Unhedged international bonds expose investors to currency moves; if the foreign currency appreciates, returns improve; if it depreciates, returns suffer.
- Currency hedging via forwards locks in an exchange rate today and removes FX volatility, but the forward rate typically reflects interest-rate differentials, which embed a cost.
- If foreign yields are lower than U.S. yields (e.g., German Bunds at 2.4% vs. U.S. Treasuries at 4.2%), hedging removes the yield advantage, making unhedged or unhedged positioning more attractive.
- Conversely, if foreign yields are higher (e.g., Mexican bonds at 7% vs. Treasuries at 4.2%), hedging costs are offset, and hedged bonds remain attractive.
- Over very long periods, the hedging cost mathematically equals the interest-rate differential; excess returns come from currency forecasting (predicting FX moves), not from the hedge itself.
The mechanics of currency-hedged ETFs
Currency-hedged ETFs (e.g., HEWG for hedged German Bunds, ESGD for hedged developed-market bonds) use forwards to lock in exchange rates and eliminate FX volatility from the investor's perspective.
Example: A U.S. investor buys HEWG (iShares Currency Hedged MSCI Germany ETF, which holds German bonds) on January 15, 2024. The spot EUR/USD exchange rate is 1.10 (one euro buys 1.10 dollars). The ETF holds EUR-denominated bonds yielding 2.4%. Without a hedge, the ETF's USD return is 2.4% (bond return) plus or minus the EUR/USD appreciation/depreciation.
With a currency hedge, the ETF manager executes a forward contract: sell EUR forward 12 months at a predetermined rate (say, 1.0850). This forward rate is lower than the spot rate (1.10) because U.S. interest rates (4.2%) exceed German rates (2.4%), and the forward reflects this differential.
The implied financing cost is: (1.10 — 1.0850) / 1.10 = 1.36% cost over one year, or approximately 136bp. This is close to the 180bp interest-rate differential; the difference reflects bid-ask spreads and other transaction costs in forward markets.
After hedging, the ETF's USD return is: 2.4% (bond yield) — 1.36% (hedging cost) = 1.04% USD return. Compare this to a U.S. Treasury ETF yielding 4.2%, and the hedged Bund ETF is unattractive.
An unhedged IGEQ (iShares Currency Hedged MSCI Germany ETF) versus EWG (iShares MSCI Germany ETF) comparison in 2024:
- Unhedged EWG: 2.4% Bund yield + FX return. If EUR appreciates 2%, total return is 4.4%; if EUR deprecates 2%, total return is 0.4%.
- Hedged IGEQ: 2.4% — 1.4% hedging cost = 1.0% return, regardless of EUR/USD move.
The decision is clear: if you believe EUR will appreciate (FX will gain), buy unhedged. If you believe EUR will depreciate or are indifferent on FX, the hedged product's 1.0% return is still worse than a U.S. Treasury's 4.2%.
When hedging costs are absorbed by yield pickups
The equation changes when international yields are higher than U.S. yields.
Consider a Mexican bond yielding 7% versus a U.S. Treasury at 4.2%. The interest-rate differential is 280bp, favoring Mexico. Currency hedging via a forward would cost approximately 280bp, lowering the effective yield to 7% — 2.8% = 4.2%, matching the Treasury yield.
But if you believe the Mexican peso will depreciate only 1% per year (less than the 2.8% implied by interest-rate parity), you are better off unhedged:
- Unhedged: 7% yield — 1% currency loss = 6% USD return.
- Hedged: 4.2% return.
- Unhedged wins by 180bp.
If you believe the peso will depreciate 3% per year (more than the interest-rate parity), hedging is justified:
- Unhedged: 7% yield — 3% currency loss = 4% USD return.
- Hedged: 4.2% return.
- Hedged wins by 20bp.
This illustrates the core principle: the forward rate embedded in hedging is an unbiased estimate of the future spot rate, conditional on interest-rate parity. If you believe the forward is wrong (i.e., the currency will move differently than implied by rate differentials), you can outperform by taking a currency view.
Portfolio construction: hedged, unhedged, and hybrid approaches
Institutional investors often split international bond allocations between hedged and unhedged to balance return and risk:
Example Portfolio: 100m AUM (Assets Under Management)
- 40m in unhedged EMD (hard-currency), yielding 6% gross, expecting 2–3% currency appreciation over the cycle, targeting 8–9% annual return.
- 30m in hedged developed-market bonds (Bunds, Gilts, JGBs), yielding net 1.5–2% after hedging, providing ballast and diversification.
- 30m in U.S. Treasuries and IG corporate bonds, yielding 4.2%.
The portfolio's expected return: (40m × 8.5% + 30m × 1.75% + 30m × 4.2%) / 100m = 3.4% + 0.525% + 1.26% = 5.185% blended.
The risk profile:
- Unhedged EMD contributes currency risk (2–3% standard deviation from FX moves) plus credit risk.
- Hedged developed-market bonds contribute only credit risk, no FX risk, and act as ballast.
- U.S. Treasuries contribute interest-rate risk and are the anchor.
The portfolio's total volatility is lower than an all-unhedged international allocation because the hedged portion dampens FX swings.
For a retail investor with a 500k portfolio, a simpler approach:
- 50k (10%) in unhedged international bonds (EMD ETF, tracking EMB).
- 450k in U.S. bonds and stocks.
The 10% international allocation captures return opportunity without complexity; FX risk is small relative to overall portfolio risk.
Dynamic hedging: adjusting based on interest-rate view
Some institutional managers use dynamic hedging: they adjust the hedge ratio based on their view of future interest rates and currencies.
If a manager believes the Federal Reserve will cut rates (and rates in Europe will stay flat), the USD will likely depreciate, making unhedged positions attractive. The manager might reduce hedging (sell fewer forward contracts) to capture the anticipated FX move.
Conversely, if the manager expects U.S. rates to rise faster than European rates, the USD will likely appreciate, making hedging more valuable. The manager increases the hedge ratio.
This dynamic approach requires skilled FX forecasting and active monitoring. Most retail investors lack the expertise or data access for dynamic hedging; a static allocation (e.g., 50% hedged, 50% unhedged) is more practical.
The costs of hedging over time
Over decades, the hedging cost equation is mathematically tight. If U.S. rates exceed foreign rates by 200bp, the forward exchange rate will depreciate the foreign currency by approximately 200bp per year (in expectation). The hedged bond return equals the bond yield; the unhedged return equals the bond yield minus the currency depreciation. In expectation, they are equal.
However, currency movements are volatile and unpredictable. In some years, the foreign currency appreciates more than interest-rate parity predicts, making unhedged positions outperform. In other years, it depreciates more, and hedged positions outperform. A manager who correctly times the hedging decision can add significant alpha; one who is wrong can detract.
For most investors, the decision is not forecasting, but preference: do you want volatility reduction (hedged), return potential (unhedged), or a mix? A 60-year-old retiree seeking stable income might prefer hedged international bonds to eliminate FX noise. A 30-year-old with a long time horizon might prefer unhedged to capture long-term currency appreciation (or depreciation) as it unfolds.
Practical execution: choosing between ETF products
U.S.-listed ETFs offer both hedged and unhedged versions of international bond indices:
- Unhedged developed-market bonds: BNDX (Vanguard), IBOXX (iShares). Expense ratio ~0.06–0.07%.
- Hedged developed-market bonds: ESGD (iShares), HEDJ (Wisdomtree). Expense ratio ~0.15–0.18%.
- Unhedged EMD: EMB (iShares), EMBD (Vanguard). Expense ratio ~0.05–0.07%.
- Hedged EMD: Not widely available; most retail investors use unhedged EMD because hedging costs are high (EMD yields are already high, and hedging adds costs).
The hedging ratio can also be controlled by position-sizing. An investor wanting 50% hedged, 50% unhedged exposure could:
- Buy 50 units of unhedged BNDX and 50 units of hedged ESGD.
- Or buy 100 units of unhedged BNDX and short 50 units of EUR/USD forward (DIY hedging).
Option 1 is simpler for retail investors. Option 2 is more tax-efficient and flexible but requires access to currency forwards.
Next
Currency decisions cascade through international bond portfolios. The next article steps back to examine how investors allocate between bonds and equities dynamically—shifting the strategic bond allocation based on relative valuations and market conditions—a higher-level question than which bonds to buy.