How to Avoid Currency Conversion Pitfalls When Investing in US Stocks as a European

Investing in US stocks from Europe offers access to the world’s largest companies — but every euro you convert to dollars can quietly erode your returns if you don’t pay attention to currency conversion fees. In this tutorial, you’ll learn exactly how to spot, compare, and minimise these hidden costs using real EUR-based examples and actionable strategies for 2026. We’ll focus on Trade Republic, DEGIRO, and Interactive Brokers, with practical steps and pro tips for each platform.

Step 1: Understand How Currency Conversion Works With US Stocks

What to do: Before making your first US stock or ETF purchase, check how your broker handles EUR to USD conversion. This usually happens automatically when you buy US assets, but fees and rates differ by platform.

Why it matters: Currency conversion isn’t free. Most brokers add a markup (“spread”) or fee on top of the real market EUR/USD rate. Over time, these costs compound — even small differences can eat hundreds of euros from your returns, especially if you invest regularly or rebalance your portfolio often.

• Trade Republic: Applies a 0.5% FX fee per trade involving currency conversion.
• DEGIRO: 0.25% automatic FX fee, or choose manual conversion at €10 + 0.02% per conversion (useful for larger sums).
• Interactive Brokers: Charges a flat $2 per conversion (up to $100,000), with negligible spread. For frequent or high-volume investors, this is typically the lowest-cost option.

What can go wrong: If you ignore FX fees, you might think you’re getting a great deal — but over years, even a 0.3% difference can reduce your ending portfolio by thousands of euros. Always check your broker’s official pricing and compare with your investment plan.

Step 2: Calculate the Real Impact of Currency Fees With EUR Examples

What to do: Use a simple EUR/USD conversion calculator or spreadsheet to compare the net amount of US stocks you’ll actually receive after fees. Let’s walk through an example:

• You want to invest €10,000 in a US ETF (e.g., Vanguard S&P 500 UCITS ETF USD (IE00B3XXRP09)).
• Assume the mid-market EUR/USD rate is 1.10.

Expected outcome: With no fees, €10,000 × 1.10 = $11,000 to invest in US stocks.

Now compare brokers:

• Trade Republic (0.5% FX fee): €10,000 × 1.10 × (1 - 0.005) = $10,945
• DEGIRO (0.25% auto FX): €10,000 × 1.10 × (1 - 0.0025) = $10,972.50
• Interactive Brokers ($2 flat): €10,000 × 1.10 = $11,000 - $2 ≈ $10,998 (assuming $2 is ~€1.82 at this rate)

Over 10 years: If you invest €10,000 annually, a 0.5% fee versus a 0.02% fee may cost you over €500–€1,000 in lost returns, not counting compounding effects.

Step 3: Choose the Right Broker and Conversion Method for Your Needs

What to do: Decide between automatic broker conversion (quick and easy, but may be pricier) or manual conversion (more control and often cheaper for large amounts).

• Trade Republic: No manual option — all EUR/USD conversions are automatic at 0.5% fee per trade.
• DEGIRO: Go to Account → Currency Settings → Manual Conversion. Convert EUR to USD in one transaction, then use the USD cash balance to buy US stocks. Manual conversion is €10 + 0.02% per conversion, making sense for amounts above ~€5,000.
• Interactive Brokers: Use the “Convert Currency” tool. In the web app, go to Transfer & Pay → Convert Currency, enter your EUR amount, and confirm the trade. Fee is $2 per conversion, regardless of size (up to $100,000).

Why it matters: With manual conversion, you avoid repeated FX fees on every purchase. This is especially valuable if you plan to make several US stock purchases, or set up a recurring investment plan.

What can go wrong: If you forget to manually convert and buy US stocks directly, you’ll pay the higher automatic FX fee every time. Also, holding a USD cash balance exposes you to EUR/USD exchange rate movements.

Step 4: Optimise Your Order Strategy to Minimise FX Costs

What to do: Consolidate your US stock purchases to reduce the number of FX conversions. For example, convert a larger sum once per quarter, rather than converting small amounts every week.

• On DEGIRO, use manual conversion for quarterly or semi-annual lump sum investments.
• On Interactive Brokers, batch your EUR → USD conversions and then make multiple US stock purchases from your USD balance.
• On Trade Republic, you have less flexibility, but you can still reduce costs by investing in larger, less frequent amounts.

Expected outcome: By reducing the number of conversions, you minimise the cumulative effect of FX fees and take better advantage of lower per-transaction costs (especially on DEGIRO and Interactive Brokers).

Step 5: Monitor and Review Your FX Costs Regularly

What to do: After each US stock or ETF purchase, check your broker’s transaction report for the exact EUR/USD rate used and the fee charged. Track these in a spreadsheet to spot trends or unexpected charges.

• On Trade Republic, tap Account → Documents → Trade Confirmations to view FX details for each transaction.
• On DEGIRO, download your activity statement from Account → Reports.
• On Interactive Brokers, go to Reports → Statements → Activity, and review the FX conversion section.

Why it matters: Brokers may change FX fees, or apply different rates for different types of trades (e.g., savings plans vs. one-off purchases). Only by tracking your actual costs can you be sure you’re not leaking returns.

What can go wrong: If you don’t monitor your FX costs, you might miss fee increases or fail to spot more cost-effective options as your portfolio grows.

Common Mistakes When Converting Currency for US Stocks

• Ignoring FX fees: Assuming they are negligible, when over time they add up significantly.
• Frequent small conversions: Making lots of small EUR→USD trades, which multiplies total fees.
• Not using manual conversion when available: Missing out on lower fees for large or batched conversions (especially on DEGIRO and Interactive Brokers).
• Not checking actual execution rates: Relying on “mid-market” rates shown on Google or XE, which are never the rates you receive from brokers.
• Assuming all brokers are the same: FX fees can vary tenfold between platforms, seriously impacting long-term returns.

Next Steps

• Review your broker’s current FX fee schedule before your next US stock or ETF purchase.
• Consider consolidating US investments to reduce the number of conversions.
• Test manual conversion (if available on your broker) with a small amount to understand the process and fees.
• Explore How to Buy US Tech Stocks as a European Investor in 2026: Step-by-Step With Screenshots for a walkthrough of trading US stocks from Europe.
• For more on optimising your overall portfolio, revisit Mastering ETF Asset Allocation: A European Investor’s 2026 Roadmap.

Disclaimer: This article is for educational purposes only and does not constitute financial advice. Always do your own research and consider consulting a qualified financial advisor before making investment decisions.