Currency risk: how rupee–dollar moves change your US returns

When an Indian resident invests in US stocks, every position is implicitly two bets: a bet on the underlying stock or ETF, and a bet on USD/INR. Most retail investors think only about the first one. The second is doing more work in your portfolio than you realize.

This post unpacks what currency risk actually does to your returns, when it works in your favor, when it doesn't, and how to size your US allocation taking it into account.

The two-leg return decomposition

Suppose you invest ₹10 lakh in VTI on a day USD/INR is ₹83. Three years later, you sell.

Your INR return decomposes into two parts:

1. The asset return (in USD): how much VTI moved.
2. The currency return (USD/INR): how much the rupee moved against the dollar.

Mathematically:

INR return ≈ USD return + INR depreciation

(Strictly, it's multiplicative — (1 + USD return) × (1 + currency move) − 1 — but for typical numbers the additive approximation is close.)

Worked example: rupee depreciates

You invest ₹10 lakh. USD/INR moves from ₹83 to ₹86 over 3 years (3.6% INR depreciation, or ~1.2% per year). VTI gains 30% in USD over the same period.

	Value
Initial investment	₹10,00,000 = $12,048
End USD value	$12,048 × 1.30 = $15,663
End INR value	$15,663 × ₹86 = ₹13,47,000
INR return	₹3,47,000 = 34.7%
Of which, asset contribution	~30% (the stock move)
Of which, currency contribution	~3.6% + small cross term

The rupee depreciation added 3.6% to your INR return on top of the stock's gain.

Worked example: rupee strengthens

Now flip it. USD/INR moves from ₹83 to ₹80 over 3 years (3.6% INR appreciation). VTI still gains 30% in USD.

	Value
Initial investment	₹10,00,000 = $12,048
End USD value	$15,663
End INR value	$15,663 × ₹80 = ₹12,53,040
INR return	25.3%
Currency contribution	−3.6%

The 30% USD gain became a 25.3% INR gain. Currency worked against you by 3.6%.

Worked example: stock flat, currency moves

If VTI doesn't move (0% USD return) but USD/INR goes from ₹83 to ₹86, your INR return is +3.6% on a stock that did nothing. Pure currency.

If VTI doesn't move but USD/INR goes from ₹83 to ₹80, your INR return is −3.6%. You lost money holding a flat asset.

What does the rupee actually do?

Looking at long-term USD/INR history:

Period	Approximate USD/INR start → end	INR depreciation (annualized)
1990–2000	₹17 → ₹46	~10% per year
2000–2010	₹46 → ₹45	~0% (rupee stable)
2010–2020	₹45 → ₹75	~5% per year
2020–2025	₹75 → ₹85	~2.5% per year

The historical average rupee depreciation against the dollar is roughly 3–4% per year over multi-decade horizons, but it's highly uneven. Decade-long stretches of essentially zero movement (the 2000s) have happened. Sharp depreciations have also happened (1991 devaluation, 2013 taper tantrum, 2022 Fed-tightening cycle).

You should not assume the rupee will depreciate at any particular rate going forward. The structural drivers (current account deficit, inflation differential vs. US, capital flow regime) point toward continued depreciation, but the magnitude is uncertain.

What this means for your US portfolio

The "natural hedge" view

If your spending is mostly in INR but you import services priced in USD (foreign software subscriptions, education abroad for kids, international travel), your effective expenses include a USD component. Holding USD assets hedges this implicit dollar liability.

For an upper-middle-class urban Indian household:

• ~70–85% of spending is INR-denominated (rent, food, local services).
• ~15–30% has implicit USD exposure (electronics, foreign travel, education, SaaS).

So holding some USD-denominated assets is a structural hedge, not a speculation. The right amount roughly mirrors your USD spending share — 20–30% of long-term assets in USD is defensible on hedging grounds alone.

The "you're concentrating risk" view

The opposite take: India is your home country. Your salary is INR. Your real-estate is in INR. Your retirement savings (PPF, EPF, NPS) are INR. Adding US-denominated equity adds currency risk on top of equity risk.

This is also true. The way to think about it: your US allocation introduces dollar risk in exchange for diversification and access to companies you can't get domestically. The dollar risk is the cost of admission.

How much is "too much" US?

For most working Indian professionals, the right US-equity allocation is somewhere between 20% and 40% of total long-term assets. The reasoning:

• Below 20%: you're not getting meaningful diversification benefit. The rest of your portfolio dominates.
• 20–40%: real diversification with manageable currency risk.
• Above 40%: starting to take a meaningful currency view. Defensible if you have specific reasons (USD-denominated future spending, plan to emigrate, etc.) but not the default.

Above 60% is a strong currency bet. Most retirees in any country don't hold 60% of their assets in a foreign currency unless they're explicitly preparing to relocate.

Currency risk and time horizon

Short-term currency moves are noisy. The standard deviation of annual USD/INR moves is around 5–6%. The mean drift is 3–4% (depreciation).

This means:

• Over 1 year, the noise dominates. The currency could move 10% in either direction.
• Over 5 years, the drift starts to dominate. Cumulative depreciation of 15–20% is plausible.
• Over 20+ years, the drift dominates strongly. Cumulative depreciation of 40–60% is more likely than not.

The implication: for short holding periods, currency is a roulette wheel. For long holding periods, currency is more predictably tilted in your favor (as an Indian holding USD assets). This is one reason the LRS framework punishes short-term US trading and rewards long-term holding — the currency drift compounds over time.

Hedging — and why it usually doesn't make sense for Indian retail investors

In theory, you could hedge USD exposure by buying INR-strengthening derivatives or short-USD positions. In practice:

• Derivatives trading abroad is not permitted under LRS for Indian residents.
• Indian-listed currency futures exist but require derivatives accounts and active management.
• The cost of hedging (forward premium of about 3–4% per year on USD/INR) usually equals or exceeds the expected depreciation drift, eliminating the benefit.

For retail investors, the practical answer is: don't hedge. Size your USD allocation such that you can tolerate the volatility. That's typically 20–40% of long-term assets.

A sizing framework

Here's a simple way to think about how much US equity you should hold:

Step 1: Calculate your "USD-flavored" liabilities

Sum up annual spending that's USD-denominated or correlated:

• Software subscriptions (Netflix, Spotify, AWS, Adobe, etc.).
• Foreign travel (typically 20–40% of total trip cost is USD-influenced).
• Foreign education (if relevant — full USD).
• Imported electronics, branded goods.

For a typical urban household: ~₹2–5 lakh/year of USD-flavored spending.

Step 2: Estimate retirement-period USD spending

Will you continue traveling internationally in retirement? Send kids abroad for education? Maintain SaaS subscriptions? If so, your retirement portfolio should support some USD spending.

A rough rule: if your retirement spending will be ~₹50 lakh/year and ~₹10 lakh of that is USD-flavored, you want your retirement portfolio to be ~20% USD-denominated.

Step 3: Add a diversification premium

Even beyond pure hedging, having 20–30% of equity in non-Indian assets gives you index-level diversification benefits. Add another 5–10% on top of pure hedging needs.

Result: 20–40% of long-term equity in US/foreign assets is a sensible default for a middle/upper-middle-class Indian household.

Currency and rebalancing

Once you have a target allocation (say, 30% US / 70% Indian), the currency moves will push you off target. If the rupee depreciates 10%, your US allocation grows in INR terms even without stock moves.

The question: do you rebalance back toward the target?

Yes — but not constantly. A reasonable rule:

• Rebalance when allocation drifts by more than 5 percentage points from target.
• Rebalance no more often than once a year.
• When rebalancing, use new contributions (direct fresh capital to the underweight asset) rather than selling overweight assets if possible. Selling triggers tax events.

If your target is 30% US and the actual is 38% (rupee weakened, US stocks rallied), don't immediately sell US. Instead, direct the next 6 months of new investments to Indian assets to bring the ratio back toward 30%.

Common currency mistakes

Mistake 1: Trying to time the rupee

"I'll wait for USD/INR to drop before remitting more." Almost always wrong. The rupee has consistently depreciated, not strengthened, over multi-decade horizons. Waiting costs you in expected value.

The right behavior: systematic remittance. Send a fixed INR amount quarterly or monthly. Take the average rate.

Mistake 2: Treating currency gains as "real" gains

If your portfolio is up 10% and 6% of that is rupee depreciation, your real dollar-asset return is only 4%. Don't congratulate yourself for currency drift; that's exposure outcome, not skill.

Mistake 3: Ignoring currency in tax math

Indian capital gains tax is computed on INR proceeds minus INR cost basis. Currency moves create taxable gains even when the underlying USD asset is flat. We covered this in the tax post — re-read it. The currency leg of your gain is fully taxable.

Mistake 4: Holding too much USD because "the rupee will crash"

The contrarian extreme. People who go 80%+ USD because they're convinced the rupee will collapse. The rupee has weakened steadily but slowly; "crashes" are rare. A 60%+ USD allocation makes sense only if you're explicitly planning to emigrate or your spending is genuinely majority-USD.

For most Indians who plan to remain Indian residents: 20–40% USD is plenty.

Mistake 5: Not reassessing as life changes

If your kids are 5 years old today, your planned international education spending is far in the future. Currency risk has more time to play out. As they approach 18, the foreign education spending becomes near-term — currency volatility matters more. Your USD allocation should track this.

Same for emigration plans, retirement timelines, etc. Currency exposure is a function of when you'll spend the money, not just whether.

A concrete portfolio example

For a 35-year-old urban Indian professional with ₹1 cr investable assets:

Allocation	Amount	Currency
Indian equity (index funds, large-cap)	₹40 lakh	INR
Indian debt (PPF, NPS, EPF)	₹20 lakh	INR
US equity (VTI + QQQM)	₹25 lakh	USD
International developed (VEA)	₹5 lakh	USD-ish
Indian real estate (home)	(excluded from "investable" for sizing)	INR
Cash buffer	₹5 lakh	INR
Gold (sovereign gold bond)	₹5 lakh	INR-ish

USD exposure: 30% of investable assets. Reasonable for someone with foreign-software-flavored expenses, plans to travel internationally, possibly send kids abroad for higher education.

If the rupee depreciates 10% over 3 years, the USD allocation grows to ~₹33 lakh in INR terms. The portfolio total grows ~₹3 lakh just from currency. Treat it as part of the diversification working as intended.

The summary

Currency risk is the second leg of every US investment. For Indian residents:

1. The rupee has historically depreciated ~3–4% per year against the dollar, but with significant variability.
2. Holding USD assets is a partial hedge against your USD-flavored expenses.
3. 20–40% of long-term assets in USD is sensible for most upper-middle-class urban households.
4. Don't try to time the rupee. Systematic remittance beats timing.
5. Don't hedge with derivatives — for retail Indians under LRS, hedging usually costs more than the expected currency drift.

The currency leg works in your favor over decades, against you in shorter windows, and doesn't predict either your short-term portfolio performance or whether you should invest at all. Get sized right and stop thinking about it.