Fact checked by Vikki Velasquez
Key Takeaways
-
Thematic ETFs have gained popularity because they allow for concentrated bets on trends or ideas.
-
The funds have higher expense ratios than broad index-tracking ETFs.
-
They often make undiversified bets on a specific sub-sector, such as robotics or data centers in the technology industry.
-
Thematics offer the potential for outsize gains, but also bring concentration risks if the idea doesn’t work out.
-
It’s wise to limit exposure to levels that correspond with your goals, risk tolerance, and time horizon.
Want to bet how the future will unfold? There’s most likely a thematic exchange-traded fund for that. These ETFs focus on a specific investment theme, from all-in bets on artificial intelligence to targeted stakes in crypto firms.
Unlike sector ETFs, thematics can choose companies from across industries as long as they have a business related to the fund’s thesis. So if you have a conviction about what companies will dominate the future, buying a corresponding thematic ETF can be an easy way to back it up.
But figuring out just how big such a bet should be is far more difficult. Commit too little and the returns will barely register, even if you’re right. Wager too much, and you risk losing your nest egg if you’re wrong.
Why Investors Use Thematic ETFs
Using ETFs to build a portfolio of passive index-tracking funds has clear benefits, but for some investors, it’s, well, perhaps a bit boring. Sometimes investors want to concentrate a bet on a specific trend or idea they think will reshape the economy. That’s where thematic ETFs come into play.
Instead of tracking, say, technology or healthcare firms writ large, a thematic ETF targets very specific sub-trends such as autonomous vehicles or genomics. The ETF holds multiple companies with significant exposure to the chosen subsector, allowing investors to back the theme in a single trade without having to pick which individual companies.
Because they are often hyper-focused, the potential exists for greater payoffs. But if the trend doesn’t pan out, the funds’ holdings will likely suffer heavy losses.
Thematic ETFs have grown in popularity in recent years, amassing a three-year high of $779 billion in assets as of the third quarter of 2025, according to Morningstar’s Global Thematic Fund Landscape report.
Note
As of May 2026, the biggest thematic ETF by assets was the iShares A.I. Innovation and Tech Active ETF.
Why Allocation Matters
Financial planners advise clients to spread risk in their portfolios across sectors, countries, and asset classes. Thematic ETFs can undermine that approach because of their narrow focus. They can be more prone to large price swings than broad-market ETFs that track major indexes, even if they spread exposure across multiple companies.
Thematic funds also tend to charge higher fees, which eat into returns. Often, they launch right after a theme has become popular, meaning investors may risk buying in too late to capture the explosive growth.
The overall performance stats aren’t great. According to Morningstar, more than half of thematic funds failed to survive the 15 years to mid-2024. Only 9% survived and outperformed a global equity benchmark over the trailing three years starting in June 2024.
That’s not to say they should be avoided altogether, and certainly thematic ETFs remain popular. But the data makes a solid case for not overexposing yourself. Ideally, they should make up a small enough part of a diversified portfolio that a major setback doesn’t torch your savings.
Important
The average expense ratio for thematic ETFs is just over 0.6%.
One Approach: Core-Satellite Investing
One way asset managers recommend sizing thematic bets is through core-satellite investing.
The idea is to split your portfolio into two parts. The core, roughly 70% to 80% of your money, sits in broad, low-cost index funds that track the overall market. This foundation provides diversification across companies and sectors.
The remaining slice, the satellite, is where thematic ETFs and other higher-risk investments, such as individual stocks, live. If the theme pays off, you get meaningful upside. If it doesn’t, the damage is contained.
The exact split between core and satellite isn’t fixed and depends on how much risk you’re willing to take. Decide on an allocation that fits your circumstances before investing, with guidance from a financial planner if needed. And don’t let a good or bad run prompt you to impulsively change course.
Questions to Ask Before Investing
Several factors can help you decide how much exposure is appropriate and which thematic ETFs, if any, to invest in. Key questions to ask include:
-
What are your investment goals and time horizon? Are you investing for retirement decades away, or a shorter-term goal? Thematic exposure is generally easier to justify when you have a long enough time horizon to ride out volatility.
-
How much risk can you tolerate? Concentrated bets can produce sharp drawdowns. Be honest about how much of a swing you can stomach without abandoning the position at the worst time.
-
How concentrated is the fund? Look at the number of holdings and the weightings of the largest positions. A fund focused on a narrow theme may hold relatively few stocks, or a small handful may account for a large share of total assets.
-
How much exposure to the theme does it offer? Some thematic funds own large companies that only earn a small share of their revenue from the marketed theme. A cloud-computing fund might hold Amazon because of AWS, even though the unit accounts for less than 20% of the company’s total revenue.
-
Does it overlap with what you already own? Many thematic ETFs are dominated by the same mega-cap companies already sitting in core index funds.
-
Am I chasing performance? Themes often attract the most money right after a strong run, which is also when valuations are already elevated.
-
When would you sell? A theme that looks obvious today may never play out as expected. Before investing, it’s a good idea to determine what would make you sell. If you don’t, you risk making an emotional decision.
The Bottom Line
Thematic ETFs appeal because they target potentially transformative trends with huge growth potential. They aren’t a safe, diversified play, though, since they represent a narrow bet that could take years to play out.
So it’s wise to limit your exposure to levels that correspond with your goals, risk tolerance, time horizon, and what your existing portfolio already owns.
For most investors, thematic ETFs work better as a satellite position than as the core holding. Keeping the bulk of your money in broad, diversified funds lets you pursue a high-conviction bet without staking your whole portfolio on it.
Read the original article on Investopedia