Foreign Investment in U.S. Equities During a Weaker U.S. Dollar Cycle

When allocating capital to U.S. equities, foreign investors experience a dual return structure: equity performance and currency translation. In periods where the U.S. dollar trades at comparatively weaker levels, entry pricing in local currency may appear attractive. However, subsequent exchange-rate movement materially affects realized returns.

This paper outlines a formal return decomposition framework and provides illustrative quantitative examples to clarify how FX exposure interacts with equity performance.

For a Mexican investor, total return in MXN terms can be expressed as:

Total Return (MXN) = (1 + Equity Return USD) × (1 + FX Return) – 1

Where:

Equity Return USD = percentage change in the U.S. equity investment.

FX Return = percentage change in USD/MXN during the holding period.

FX Return is calculated as:

FX Return = (Ending FX Rate / Beginning FX Rate) – 1

Assumptions:

Beginning USD/MXN: 17.50

Investment Amount: $100,000 USD

Beginning Peso Investment: 1,750,000 MXN

Equity Performance: +12%

Ending USD/MXN: 19.00

Step 1: Calculate Equity Value

$100,000 × 1.12 = $112,000

Step 2: Convert Back to MXN

$112,000 × 19.00 = 2,128,000 MXN

Step 3: Compute Peso Return

(2,128,000 / 1,750,000) – 1 = 21.6% MXN Return

Interpretation: Both equity appreciation and USD strengthening amplified local-currency returns.

Assumptions:

Beginning USD/MXN: 17.50

Investment Amount: $100,000 USD

Beginning Peso Investment: 1,750,000 MXN

Equity Performance: +10%

Ending USD/MXN: 16.80

Step 1: Equity Value

$100,000 × 1.10 = $110,000

Step 2: Convert Back to MXN

$110,000 × 16.80 = 1,848,000 MXN

Step 3: Compute Peso Return

(1,848,000 / 1,750,000) – 1 ≈ 5.6% MXN Return

Interpretation: Despite positive equity performance, USD depreciation reduced realized MXN returns.

Assume 50% of currency exposure is hedged via forward contract at 17.50.

Equity Return USD: +10%

Spot FX at Exit: 16.80

Unhedged Portion (50%):

50% × $110,000 × 16.80 = 924,000 MXN

Hedged Portion (50% locked at 17.50):

50% × $110,000 × 17.50 = 962,500 MXN

Total MXN Value = 1,886,500 MXN

Return = (1,886,500 / 1,750,000) – 1 ≈ 7.8%

Interpretation: Partial hedging reduced currency drag while preserving some flexibility.

1. Separate strategic equity allocation from tactical currency positioning.

2. Define target hedge ratios aligned with risk tolerance.

3. Use staged entry to mitigate timing concentration risk.

4. Align USD exposure with future USD liabilities where applicable.

5. Rebalance currency exposure systematically rather than reactively.

Currency management should not be speculative in nature; rather, it should function as a risk management overlay.

A weaker U.S. dollar may present an attractive capital allocation window for Latin American investors. However, realized outcomes depend on disciplined integration of equity and currency analysis. Understanding the mathematical interaction between asset performance and FX movement is central to institutional-grade portfolio construction.