Why a "Flat Year" in Your Portfolio Might Not Be Real (The Currency Trap)
The Portfolio Diary — Part 1 of 4
One of the deciding factors in a FIRE journey is our private investments.
I spend a decent amount of time managing my stock and ETF investments — not only because I want to earn good money there, but also because I enjoy doing it.
I'd like to share with you a personal record of trading decisions I actually made in this series, The Portfolio Diary. Perhaps it can help you as you build your own investment portfolio.
This is not investment advice — just the lessons I've learned along the way.
At the end of 2025 I looked at my portfolio and thought: meh. Flat year. Nothing to write home about.
The number I was looking at: −€291.
A year of monthly contributions, a year of following the news, checking prices, second-guessing myself — and the scoreboard said I'd basically gone nowhere. Worse than putting money in a savings account.
So in January 2026 I did what felt like the responsible thing: I closed 60+ of my positions on eToro and rebuilt my ETF lineup from scratch. Clean slate, better structure, lessons applied.
Here's the thing I didn't check first.
That −€291 was the number in euros. In the currency my positions actually trade in — mostly US dollars — the same portfolio was up +€5,205 (converted at a fixed rate, so we're comparing apples to apples on "how much did the underlying stuff actually do"). Same holdings. Same year. Two numbers on two sides of zero. I realized I walked right in to the currency trap.
What actually happened
The euro strengthened against the dollar over 2025. My assets, priced and held in dollars, did genuinely fine. But every time I converted the "real" performance back into the currency I actually think in, the currency move ate the gain and then some. I read the euro number, concluded "bad year," and used that as a reason for a portfolio-wide reset.
The rebuild wasn't a disaster — it worked out fine, in fact. But that's not the point. The decision was triggered by a reading error, not a strategy error. I got lucky that acting on bad information didn't cost me. That's not something to repeat and hope for again.
The lens problem (or: the currency trap)
The mistake wasn't a math mistake. Both numbers were "correct" — they were just answering different questions. −€291 answers "how much richer am I in the currency I'll eventually spend?" +€5,205 answers "did the stuff I bought actually perform?" I needed both to understand what happened. I only looked at one, and it happened to be the one that told a scarier story.
Check what the number is actually measuring before you trust the verdict.
Is there a currency conversion hiding in there? A different calculation method than the last time you looked? A number that only shows unrealized gains and quietly excludes everything already banked? (Yes — that's also a real one I got burned by; my three brokers each calculate "P/L" differently, and none of them agree with each other by default.)
The fix that actually works, every time: current value minus what I actually put in, full stop. Not the dashboard summary. Not the "return %" some app decided to show me. Just: what's it worth now, minus what I paid for it. That number can't lie to you about currency, and it doesn't care if you sold something and rebought it the next day.
What this looks like with real positions
I went back through the actual picks to see if this "check your lens" problem shows up at the individual-stock level too. It does, just differently.
The winner: NVDA — bought in November 2022, not because I called the AI boom (that story didn't exist yet), but because it was down over 60% from its 2021 high during the worst broad selloff since 2008, right after a rough CPI print rattled everyone one more time.
On paper, in that window, it looked like exactly the kind of position a nervous investor sells. It's now up 348% all-time. If I'd read "down 60%" as the whole story instead of asking why and compared to what, I'd have made the same lens mistake as my 2025 euro number — just in the other direction.
The losers, with nothing obviously in common: Trade Desk, Sika, Wolters Kluwer, Cloudflare, and an EV/battery-metals ETF.
I went looking for the one thing they shared, expecting a lesson like "avoid this sector" or "avoid this style." There isn't one. They span defensive stocks and growth stocks, single names and a thematic ETF, industries with nothing to do with each other. No clean narrative, no single "aha." Sometimes a reasonable decision, made with a reasonable process, just doesn't work out — and hunting for a tidy explanation after the fact is its own kind of lens error.
The actual takeaway
Before I let myself conclude something underperformed — a portfolio, a position, a year — I now ask: compared to what, measured how? It's a five-minute check that would have saved me from making a decision on a false premise. The rebuild happened to work out. Next time I might not be so lucky.
Next up in this series: the actual rules I follow day to day — the boring, unglamorous ones that keep a bad week from turning into a bad decision.
This is a personal record of decisions I actually made, not investment advice or a recommendation to buy, hold, or sell anything. What worked for my portfolio, timeline, and risk tolerance may be completely wrong for yours. I'm not a financial advisor — I'm just documenting my own FIRE journey, mistakes included.
