Life in the cloud has been good in recent years, which explains why WisdomTree Investments today introduced the exchange-traded fund industry’s third product this year dedicated to this segment.

The WisdomTree Cloud Computing Fund (WCLD) tracks the equal-weighted BVP Nasdaq Emerging Cloud Index created by Nasdaq and Bessemer Venture Partners, an early-stage investor in cloud-based businesses. Companies within the index must get a majority of their revenue from business-oriented software products through a cloud delivery model that is subscription based, volume-based or transaction-based. They also must have a minimum market capitalization of $500 million and meet certain criteria for annual revenue growth and liquidity.

WisdomTree delineates the cloud industry into three categories entailing software, platforms and infrastructure. It posits that the growing adoption of cloud-based workflows by businesses, along with further advancements in artificial intelligence and the internet of things, will continue to juice the cloud industry.

This is primarily a U.S.-centric fund, with one company each from Australia and Israel among the 49 holdings. Constituents include familiar names such as Inc., ServiceNow Inc., PayPal Holdings Inc. and DocuSign Inc., along with a slew of smaller, unfamiliar companies making a name for themselves in the cloud.

WCLD charges a net expense ratio of 0.45%, making it the second-least expensive product in the small universe of four cloud-computing ETFs.

Along WCLD, the other two cloud-focused ETFs to debut this year were the Tortoise Cloud Infrastructure Fund (TCLD) and Global X Cloud Computing ETF (CLOU).

TCLD began trading in February and tracks a modified market cap-weighted index comprising companies providing cloud services, cloud-management software, data centers and cloud security. This product is the cheapest among the four cloud-computing ETFs with an expense ratio of 0.40%, but that hasn’t tickled the fancy of investors as its asset base sits at only about $4 million.

The Global X fund launched in April and follows a modified market cap-weighted index containing companies that get at least 50% of their revenue from cloud-computing activities. This is the most expensive fund in the group with an expense ratio of 0.68%, but that hasn’t deterred investors who’ve poured $518 million into the fund.

The oldest product in this category, the First Trust ISE Cloud Computing Index Fund (SKYY), debuted in 2011 and has $2.3 billion in assets. Its solid performance speaks to the health of the cloud-computing sector. Specifically, its average five-year return of 16.4% and three-year return of 20.8% has handily topped the average annual returns on the SPDR S&P 500 ETF (SPY) during those periods. SKYY charges an expense ratio of 0.60%.

While only SKYY has a measurable track record, it’s nonetheless a good one. And it’s not a stretch to imagine the cloud-computing industry going full steam ahead into the near future. These four ETFs aren’t cookie-cutter products that should be bought solely on price. The portfolios of SKYY, CLOU and TCLD have low levels of overlap by weight, according to ETF Research Center. (The WisdomTree fund is too new to compare.) That means they offer different value propositions on a fast-growing industry.