Not every investor enjoys stock picking. After all, you could identify a tremendous long-term trend to invest in, pick a stock, and then find it's the laggard of the group for some stock-specific reason.

That's why buying thematic exchange-traded funds (ETF) holding a basket of stocks often makes sense. So if you like the case for copper as a play on the electrification of the economy, there's the Global X Copper Miners ETF (COPX 0.51%).

Suppose you like exposure to electric vehicle (EV) companies like Tesla and clean energy. In that case, try the First Trust Nasdaq Clean Edge Green Energy Index ETF (QCLN 0.45%).

And if you like infrastructure investment, there's the iShares Global Infrastructure ETF (IGF 1.13%). 

A copper miner ETF

The case for copper is based on long-term demand driven by economic growth (copper is the most economically sensitive industrial metal due to its use across a broad swath of industries) and its importance to the clean energy transition.

For example, EVs require significantly more wiring than a typical vehicle. Copper is also a key material in renewable energy -- notably batteries -- and the transmission and distribution networks needed to support its growth. 

Meanwhile, supply constraints are likely, given that increasing environmental and regulatory concerns make acquiring permits harder.

Freeport-McMoRan is an outstanding stock to play the theme of rising copper prices, but if you want an ETF, then the Global X Copper Miners ETF (which has Freeport as a top-10 holding) will fit the bill. 

With holdings in miners based in countries including Canada, the U.S., Australia, Poland, Japan, and China, it gives investors global exposure to the theme while helping avoid the stock-specific risk associated with investing in any one miner. Throw in a near 3% dividend yield, and the ETF is attractive for copper enthusiasts. 

A clean energy ETF to buy

The First Trust Nasdaq Clean Edge Green Energy Index ETF is attractive because it gives investors broad-based exposure to many different investment themes in the clean energy transition.

For example, its most significant holdings are in companies like ON Semiconductor (intelligent power and sensing solutions for EVs), Tesla, Enphase Energy (residential and commercial solar power storage), Rivian Automotive, and Albemarle (lithium for EV batteries).

As you can see from this short list, the ETF gives exposure to different themes and obviates the need to try to pick winners in a growth industry. It's an approach that will limit returns compared to the highest-performing stocks in the sector. Still, it's not easy to find those stocks, and nothing is more frustrating than investing in a successful theme only to find you are holding an underperformer in the sector. 

As such, investors who want exposure to clean energy without taking a strong position in any sub-theme or stock will want to participate in this sort of ETF. 

A genuinely global infrastructure ETF

The iShares Global Infrastructure ETF specializes in infrastructure equities in developed markets. It is heavily invested in transportation, utilities, and energy stocks, and has 61% of its holdings in international equities.

Holding no more than 6% in any one equity, the ETF invests in stocks as diverse as Australian toll road operators, Spanish airport operators, energy pipelines, and renewable energy companies. 

Infrastructure stocks are attractive in the current environment because these companies are a crucial component of the economy, and there's a need to play catch-up on infrastructural spending in the developed world -- as evidenced by the $1.2 trillion infrastructure bill in the U.S. Furthermore, developing countries need to build out infrastructure to support growth. 

Its 0.4% expense ratio compares favorably to the Global X Copper Miners ETF at 0.65% and the First Trust CleanEnergy's 0.58%. And together with the near 2.7% dividend yield the iShares ETF offers investors, it is an excellent way to get exposure to infrastructure while earning income along the way.