Top Thematic ETFs: Best Funds for Theme Investing in 2026
What Are Thematic ETFs?
Thematic ETFs are exchange-traded funds that invest around a specific investment theme—a broad, structural trend or megatrend that cuts across traditional industries and sectors. Unlike sector ETFs, which follow established GICS classifications, thematic ETFs are forward-looking, designed to capture the growth of emerging trends such as artificial intelligence (AI), cybersecurity, clean energy infrastructure, robotics, genomics, and more.
These funds attract investors who want to express a high-conviction view on a macro trend without picking individual stocks. Because themes can span multiple sectors, thematic ETFs often deliver differentiated exposure that a traditional sector fund cannot replicate.
Why Thematic ETFs Are Growing in Popularity
The thematic ETF universe has exploded over the past decade. As of 2026, there are 393 thematic ETFs listed in U.S. markets, collectively managing more than $256.69 billion in assets. The average expense ratio across the category is 0.63%, reflecting the active or specialized research required to construct and maintain theme-based portfolios.
Several tailwinds are driving growth in the space: the democratization of ETF investing, the rise of mega-trends like AI and clean energy, and increased investor appetite for portfolio customization. Thematic ETFs offer a convenient, diversified, and liquid vehicle to gain exposure to these trends at a fraction of the cost of active mutual funds.
Top Thematic ETFs by Assets Under Management
Below are the largest thematic ETFs currently trading in the U.S. market, ranked by total assets under management (AUM).
1. BAI – iShares A.I. Innovation and Tech Active ETF
AUM: $13.73B | Expense Ratio: 0.55% | 3-Month Return: 38.0%
The BAI ETF from BlackRock is the largest thematic ETF by AUM and the standout performer over the past quarter. As an actively managed fund, BAI invests in companies at the forefront of artificial intelligence innovation and technology, including AI infrastructure providers, software companies, and chip makers. Its remarkable 38% three-month return underscores just how dominant the AI theme has been in 2026.
2. PAVE – Global X U.S. Infrastructure Development ETF
AUM: $13.26B | Expense Ratio: 0.47% | 3-Month Return: 8.6%
PAVE offers investors targeted exposure to U.S. infrastructure development, focusing on companies involved in raw materials, heavy equipment, engineering, and construction. With billions in federal infrastructure spending flowing into the economy, PAVE has become one of the most popular thematic plays available to investors.
3. IGF – iShares Global Infrastructure ETF
AUM: $10.65B | Expense Ratio: 0.39% | 3-Month Return: 4.7%
For investors seeking a global infrastructure angle, IGF is the go-to option. This BlackRock fund tracks the S&P Global Infrastructure Index and provides exposure to utilities, transportation, and energy infrastructure companies around the world. Its low expense ratio makes it one of the most cost-efficient thematic ETFs available.
4. CIBR – First Trust NASDAQ Cybersecurity ETF
AUM: $10.54B | Expense Ratio: 0.58% | 3-Month Return: 9.3%
Cybersecurity remains a high-conviction theme as digital threats continue to escalate globally. CIBR tracks the Nasdaq CTA Cybersecurity Index, investing in companies engaged in building and managing cybersecurity solutions. With over $10.5 billion in AUM, CIBR is the dominant pure-play cybersecurity ETF on the market.
5. GRID – First Trust Nasdaq Clean Edge Smart Grid Infrastructure Index ETF
AUM: $10.17B | Expense Ratio: 0.56% | 3-Month Return: 16.8%
GRID invests in companies developing smart grid and electric infrastructure technologies. As the energy transition accelerates and AI-driven data center demand strains the power grid, GRID‘s 16.8% quarterly return reflects the urgent investment cycle underway in electrical infrastructure.
6. IGM – iShares Expanded Tech Sector ETF
AUM: $9.71B | Expense Ratio: 0.39% | 3-Month Return: 21.4%
IGM provides broad exposure to North American technology companies, going beyond the traditional S&P 500 tech sector to include software, internet, and semiconductor companies. It is one of the most cost-effective ways to gain diversified technology exposure within the thematic ETF universe.
7. AIQ – Global X Artificial Intelligence & Technology ETF
AUM: $8.87B | Expense Ratio: 0.68% | 3-Month Return: 20.5%
AIQ takes a developed-markets approach to the AI theme, providing exposure to companies in AI-driven applications, hardware, and services across global developed markets. Its 20.5% quarterly return reflects the broad strength of the AI thematic in 2026.
8. THRO – iShares U.S. Thematic Rotation Active ETF
AUM: $8.30B | Expense Ratio: 0.57% | 3-Month Return: 9.0%
THRO is a unique actively managed fund that rotates across multiple investment themes, allowing BlackRock’s portfolio managers to shift exposure based on market conditions and theme momentum. It provides a diversified, multi-theme approach within a single thematic wrapper.
9. URA – Global X Uranium ETF
AUM: $7.69B | Expense Ratio: 0.69% | 3-Month Return: 10.4%
URA is the leading ETF for investors seeking exposure to uranium mining and nuclear energy. As global interest in carbon-free baseload power generation surges—driven in part by the energy demands of AI infrastructure—nuclear energy has become a pivotal theme. URA is the dominant vehicle for accessing this niche but increasingly important theme.
10. GUNR – FlexShares Morningstar Global Upstream Natural Resources Index Fund
AUM: $7.46B | Expense Ratio: 0.46% | 3-Month Return: 9.1%
GUNR invests in global upstream natural resources companies, spanning energy, metals, agriculture, and timber. As a diversified commodities-adjacent thematic ETF, GUNR provides inflation-hedging characteristics while capturing the long-term demand for natural resources tied to global infrastructure investment and the energy transition.
Key Themes Dominating the Thematic ETF Landscape
Looking across the top 10 thematic ETFs by AUM, three mega-themes stand out as the most investor-favored in 2026:
Artificial Intelligence: The AI theme is by far the fastest-growing in the thematic ETF universe. Funds like BAI and AIQ have attracted tens of billions in assets as investors seek exposure to the AI revolution across hardware, software, and services. The AI theme’s 38% quarterly surge in BAI is a testament to its momentum.
Infrastructure: Both traditional and smart grid infrastructure funds dominate the rankings. PAVE, IGF, and GRID collectively manage over $34 billion, reflecting the enormous capital flowing into rebuilding and modernizing physical infrastructure worldwide.
Energy Transition: Nuclear energy (URA), smart grid (GRID), and natural resources (GUNR) all benefit from the multi-decade energy transition trend. As governments and corporations commit to decarbonization, these themes are expected to remain in strong secular demand.
Best Performing Thematic ETF of the Past Year
While the top 10 by AUM tell one story, the best-performing thematic ETF over the trailing 12 months is a different story entirely. HYDR, a hydrogen-focused thematic ETF, delivered an extraordinary 291.70% return over the past year, dramatically outpacing the broader market and all other thematic peers. This underscores an important point about the thematic ETF space: smaller, more concentrated theme funds can deliver explosive returns—but also carry significantly higher risk and volatility.
What to Consider Before Investing in Thematic ETFs
Thematic ETFs offer compelling opportunities, but they also come with unique considerations that investors should weigh carefully before committing capital.
Theme longevity: Not all themes are created equal. Some themes—like AI or infrastructure—represent durable, multi-decade structural trends backed by strong capital investment and policy support. Others may be more speculative or cyclical. Investors should evaluate whether a theme has the staying power to justify a long-term allocation.
Concentration risk: Thematic ETFs, by definition, concentrate exposure in a narrow slice of the market. This can amplify both gains and losses. Understanding the underlying holdings and their correlations is essential.
Expense ratios: The average thematic ETF charges 0.63% annually, which is meaningfully higher than broad market index funds. For long-term investors, these costs can compound significantly over time. Opt for lower-cost options like IGF (0.39%) or IGM (0.39%) where possible.
Timing and valuation: Some themes may already be priced for perfection by the time they gain mainstream attention. Entering a theme-based fund after a prolonged rally can expose investors to mean-reversion risk.
The Bottom Line
Thematic ETFs represent one of the most exciting and dynamic corners of the ETF market. Whether you’re bullish on artificial intelligence, the infrastructure buildout, cybersecurity, nuclear energy, or natural resources, there is a thematic ETF designed to match your conviction. Funds like BAI, PAVE, CIBR, and GRID have established themselves as leading vehicles for theme-based investing, each backed by billions in assets and strong track records. As always, investors should conduct thorough due diligence, understand the risks of concentrated thematic exposure, and consider their overall portfolio construction before allocating to any thematic strategy.
For a full list of all 393 thematic ETFs, including detailed performance data, fund flows, and holdings analysis, visit the ETF.com Thematic ETFs Hub.
This article was generated with the assistance of artificial intelligence and reviewed by ETF.com staff.