The Tema Space Innovators ETF (NASA) is getting a lot of attention, and for good reason. The fund just crossed $1.5 billion in assets under management less than two months after launching, making it the largest space ETF on the market despite being the sixth fund to enter the category. 

As I’ve written before, that’s largely thanks to Tema’s decision to include SpaceX shares in the portfolio. Given that SpaceX’s IPO next month is at the center of the current frenzy in space stocks, naturally that exposure has been a big draw for investors. 

Two takeaways come to mind from NASA’s success. One is that a latecomer can leapfrog older funds if it offers exposure nobody else does. The other is that private shares can be a real differentiator for thematic ETFs.

Not Just NASA

That said, NASA isn’t the only space ETF taking off.

The Procure Space ETF (UFO), one of the original space funds when it launched in 2019, just reached $1.1 billion in assets. That number sounds unremarkable for a seven-year-old fund until you remember where this fund was. 

At the end of 2024, five years after launching, UFO had just $33 million in assets. As recently as December 2025, it was around $100 million. Almost all of the growth has come in the last six months.

Meanwhile, other space ETFs are seeing big jumps also. The ARK Space & Defense Innovation ETF (ARKX) just crossed $1 billion in assets for the first time since January. 

The State Street SPDR S&P Kensho Final Frontiers ETF (ROKT), another fund that spent years in irrelevance, has rocketed to $237 million. 

The Roundhill Space & Technology ETF (MARS), which launched in early March, is at $76 million.

And even fresher entrants are getting traction, like the Global X Space Tech ETF (ORBX) with $34 million and the VanEck Space ETF (WARP) with $17 million—both after a handful of weeks on the market.

That’s three space ETFs with over a billion in AUM and several more turning into viable funds.

Under the Hood

The various space ETFs all take different approaches to the theme. NASA, ARKX, and MARS are actively managed, while UFO, ROKT, ORBX, and WARP track indexes.

I’d argue, though, that those labels don’t reveal much about what’s actually in these portfolios. Index construction can be just as discretionary as active management. You really have to look under the hood to know what exposure you’re getting.

ARKX is a good example. Nominally a space ETF, its portfolio is more like a mishmash of space, defense, broad tech and industrial names. The top holding is Rocket Lab, a pure-play space company, but the top 10 also includes Deere & Co., AMD, and Amazon.com, none of which are pure-play space names or even defense companies.

ROKT has a stated mandate covering both deep space and deep sea, but in practice it’s been much more of a space fund, with Planet Labs, Intuitive Machines, and Rocket Lab among its top positions. That mix has driven performance well ahead of both UFO and ARKX.

The newer funds, NASA, MARS, WARP, and ORBX, hold variations of relatively pure-play space portfolios. But it’s too early to draw conclusions about how they’ll perform against each other over the long term.

We’ll see what happens, but what’s clear is that space has arrived as a significant ETF category.