AI ETFs, clean energy ETFs, cybersecurity ETFs — thematic ETFs promise access to the megatrends of the future. But are they really a good investment, or are investors falling for clever marketing?

What Are Thematic ETFs?

Thematic ETFs invest in companies that benefit from a specific megatrend — artificial intelligence, renewable energy, aging populations, digitalization, space. They bet on the future rather than the status quo.

The Most Popular Thematic ETFs 2026

Artificial Intelligence: Global X Robotics and AI ETF — Performance 2024-2025: +65%
Clean Energy: iShares Global Clean Energy — Performance: +12% (recovered after -40% in 2022/23)
Cybersecurity: L and G Cyber Security ETF — Performance: +45%
Aging Population: iShares Ageing Population ETF — stable but unspectacular
Blockchain: VanEck Digital Assets ETF — extremely volatile

The Advantages

Excess returns with right timing: Those who invested in AI ETFs in 2023 massively beat the market.
Access to niches: Individual cybersecurity or space stocks are hard to identify. ETFs bundle them.
Emotional connection: Investing in themes you believe in increases holding discipline.

The Risks (and They Are Significant)

1. Entering Too Late

When a megatrend is obvious enough for an ETF launch, it is often already priced in. The best returns come BEFORE the hype — not after.

2. High Costs

Thematic ETFs typically cost 0.40-0.75% TER — three to five times more than an MSCI World ETF.

3. Concentration Instead of Diversification

An AI ETF might hold 50-80 stocks — all in the same sector. That is not diversification, that is a sector bet.

4. Arbitrary Index Construction

Who decides which companies belong to the cybersecurity theme? The index providers — with often questionable criteria.

Our Recommendation

Thematic ETFs are satellite positions, not core positions:

Maximum 5-10% of portfolio in a single theme
Maximum 15-20% in thematic ETFs total
Only themes where you can quantify the advantage over a broad index
Long-term horizon (5+ years)

Alternative: Instead of an AI ETF, buy the 3-4 strongest AI companies directly (based on AI signals). You save the high TER and have more control.

Bottom Line: Thematic ETFs are seductive — who does not want to invest in the future? But data shows: Most thematic ETFs underperform the broad market long-term. Use them sparingly and consciously.