Too many European investors are quietly sabotaging their returns—by drowning in an ocean of ETFs and stocks, all in the name of “diversification.” The financial industry has sold us the gospel of spreading risk, but have we turned prudent diversification into an obsession that’s quietly draining our euro-denominated portfolios?
Let’s be blunt. Portfolio overdiversification in Europe is killing returns. The delusion that holding 20 ETFs or 50 stocks somehow makes you “safer” is not just misguided—it may be why your wealth isn’t growing as fast as it should. Here’s why less truly is more for those who want to build serious European wealth.
The Diversification Dogma: Too Much of a Good Thing?
It’s easy to see where the cult of diversification came from. Modern Portfolio Theory, championed by Nobel laureates, taught us to avoid putting all our eggs in one basket. But here’s the unvarnished truth: the benefit of adding more assets drops off a cliff after the first few.
In Europe, holding just 5-10 well-chosen ETFs across equities and bonds gets you 95% of the diversification benefit. Adding another 10 does almost nothing—except dilute your winners and rack up fees.
Let’s put that into euros. Suppose you bought the top three broad European ETFs: iShares Core MSCI Europe (IMEU), Vanguard FTSE Developed Europe (VEUR), and Xtrackers MSCI Europe Small Cap (XXSC). In the last five years, a simple equal-weight EUR 100,000 portfolio in these three delivered around 43% total return by June 2024. But if you split that same amount across 15 overlapping regional and sector ETFs—including “smart beta” flavors—you’d have netted just 38%, after fees and ill-conceived rebalancing.
Why? Most European ETFs overlap in holdings—Nestlé, ASML, SAP crop up everywhere. You’re not diversifying; you’re just muddying the waters. The same goes for “diworsifying” pan-European stocks. The more names you hold, the closer your portfolio drifts to an expensive, underperforming index.
The Real Cost: Diluted Returns and Hidden Fees
Diversification isn’t free. Every new ETF or stock comes with its own costs—management fees, bid/ask spreads, rebalancing headaches, and the dreaded tax drag. Here’s what no one tells you:
- ETF Fees Add Up: The average total expense ratio (TER) for European-domiciled ETFs is 0.25%. Hold 10 ETFs instead of 3? You’re paying an extra €200 per €100,000 annually, often for the same underlying stocks.
- Tax Complexity: More funds means more paperwork, more withholding taxes, and more headaches for cross-border investors. If you haven’t read this guide to ETF tax traps, you’re a prime target.
- Missed Upside: In 2023, LVMH alone accounted for 40% of the gains in France’s CAC 40 index. Over-diversified investors who “trimmed” their winner in the name of rebalancing left thousands of euros on the table.
Over 60% of DIY European investors surveyed by Morningstar Europe in 2023 held more than 15 individual stocks or funds—yet their average portfolio return was 1.7% lower per year than those with just 5–8 core holdings.
More isn’t safer—it’s just more expensive, and more likely to be mediocre.
Real-World EUR Blunders: When Too Many Choices Kill Performance
Let’s look at household portfolios in Germany. According to Bundesbank data, the median German investor has 8 direct stock positions and 7 funds. Between 2018 and 2023, their five-year average return was a meagre 17%, trounced by the 31% delivered by a standard 60/40 global equity-bond ETF mix. Why the gap? Too many overlapping funds, too much home bias, and a love affair with “safe” but underperforming Eurozone sectors.
Or take Italy. A 2022 analysis by Borsa Italiana found that retail investors there held, on average, 12 different equity funds—yet their portfolios lagged the MSCI Europe Index by nearly 2% per year. Spreading bets on every sector dulled the impact of winning themes (think tech and luxury in the 2020s), while losers—banks, utilities—dragged down overall performance.
The Bottom Line
Over-diversification in European portfolios isn’t managing risk; it’s managing to kill your returns. Fewer, smarter choices beat a scattergun approach—every time.
To Be Fair: The Case for Broad Diversification
I’m not blind to the counterargument. There’s a reason diversification is a pillar of smart European investing. Black swans happen. If you were all-in on Credit Suisse in 2023, you got wiped out. If you missed Novo Nordisk, you missed the best European stock of the decade. Enough variety does insulate you from catastrophic downside.
But here’s the twist: Research from ESMA (2022) shows that beyond 10–12 uncorrelated positions, the marginal risk reduction is “statistically insignificant” for EUR portfolios. There’s wisdom in spreading risk—but folly in endlessly slicing your capital ever thinner.
How Many Funds or Stocks Should Europeans Own?
Forget the endless ETF supermarket sweep. The numbers say it all: 5–8 non-overlapping funds, or 12–20 carefully selected stocks, are enough for 99% of investors. This captures almost all the benefit, minimizes paperwork, and keeps costs down. Want proof? Europe’s best-performing pension funds rarely hold more than 8 core ETFs at a time.
Want to see what a real, streamlined approach looks like? Check out these EUR case studies of millennial ETF portfolios, which consistently outpace more complicated, over-diversified mixes.
The Verdict: Why It’s Time to Slim Down
You want my take? Most European investors need to trim the fat—now. Every extra ETF or stock you add past the first handful is a potential drag on your future wealth. Stop chasing the myth of “perfect safety” through endless diversification. The real risk is ending up average.
By 2026, the best-performing EUR portfolios will be the streamlined ones. The age of the 20-fund DIY investor is over—if you want to win, focus your firepower where it matters most.
Challenge yourself this quarter: review your holdings, cut the overlap, and re-allocate to just 5–8 rock-solid, complementary positions. Your future self—and your returns—will thank you.
Disclaimer: This article reflects the author's opinion and is for educational purposes only. It does not constitute financial advice. Always do your own research before making investment decisions.