• CNBC partnered with Fintrx to analyze single family offices that made the largest number of investments in private startups in 2024.

A version of this article first appeared in CNBC's Inside Wealth newsletter with Robert Frank, a weekly guide to the high-net-worth investor and consumer. Sign up to receive future editions, straight to your inbox.

The top 10 family offices for startup investments made over 150 investments combined this year, in everything from biotech and energy to crypto and artificial intelligence, according to a new analysis.

CNBC partnered with Fintrx, the private wealth intelligence platform, to analyze single family offices that made the largest number of investments in private startups in 2024. The list, a first of its kind, sheds light on the investments by some of the biggest names in family offices, from Bernard Arnault's Aglaé Ventures to Laurene Powell Jobs' Emerson Collective and Peter Thiel's Thiel Capital. It also reveals names that are little known outside the secretive world of family offices — the private investment arms of wealthy families — but that have become major players in the world of venture capital and private markets.

The most active family office so far this year is Maelstrom, the Hong Kong-based family office of American investor Arthur Hayes, who co-founded the crypto exchange BitMEX. Maelstrom has invested in 22 private startups this year, according to the Fintrx data, topping all other family offices in the database. The vast majority of Maelstrom's investments are in blockchain technology, including Cytonic, Magma, Infinit, Solayer, BSX, Khalani and Term Labs.

Ranking second on the Top 10 list is Motier Ventures, the family office and venture arm of Guillaume Houzé. Houzé, scion of the fabled French dynasty that owns Galeries Lafayette and other retailing giants, co-founded Motier in 2021 to invest in tech startups.

Motier has invested in 21 startups so far this year. Its investments are largely in artificial intelligence and blockchain, but also include publishing and advertising. The investments include Vibe.co, known as "the Google Ads of streaming"; Adaptive, a tech platform for the construction industry; and PayFlows, a fintech company. It was part of a $220 million seed funding round for Holistic AI, a French generative AI startup, and a $30 million seed round for Flex AI, a Paris-based AI compute company.

Motier was also an investor in two funding rounds for Mistral, the fast-growing French AI firm, which raised more than $500 million last year and whose investors include Nvidia, Lightspeed, and Andreesen Horowitz.

Tied for third are Atinum Investment, the Seoul, Korea-based family office for an unknown family that has mainly invested in software and AI; Hillspire, the family office of former Google CEO Eric Schmidt; and Emerson Collective.

Thiel Capital, tied for sixth, has invested in Fantasy Chess, founded by 17-time World Chess Champion Magnus Carlsen, as well as Rhea Fertility, a Singapore-based fertility-clinic roll-up company.

The list doesn't include the investment amounts and may not include all deals or all family offices, since they aren't required to disclose their investments. Fintrx compiles its data based on public and private sources from its team of researchers. For the sake of the list, family offices are defined as investment vehicles or holding companies of a single family or individual that don't manage money for outside investors. The investments don't include real estate.

As a whole, the ranking offers a rare window into the growing power of family offices in the world of startup capital as they've grown in size, wealth and deal sophistication. Nearly a third of startup capital in 2022 came from family offices, according to a PWC report.

AI has become their favorite investment theme for 2024, and likely will be again in 2025. According to the UBS Global Family Office Report, AI is now the favorite investment category for family offices. More than three-quarters, or 78%, of family offices surveyed plan to invest in AI in the next two to three years — the most for any category. As CNBC has previously reported, Aglaé Ventures, the tech venture arm of LVMH chief Arnault's family office, has made a string of AI investments this year. Jeff Bezos' Bezos Expeditions has also made several AI bets in 2024.

Family office advisors say serial investors like those on the Top 10 list often treat startups as idea labs — where they can learn about cutting-edge technology and markets. They can apply those learnings to larger investments or to their own companies.

Schmidt's family office, Hillspire, for instance, has made over a half-dozen investments this year in AI, which have also helped inform his big bets on energy companies, given the power needs of AI computing. Hillspire was an investor in the $900 million investment round for Pacific Fusion, a nuclear fusion startup, as well as Sion Power.

While a large number of family offices invest in tech startups through venture capital funds, the deals on the CNBC list are for investments made directly by the family offices in startups.

The biggest family offices, such as Hillspire, Thiel or Aglaé, have growing teams of deal and tech experts who can analyze investments and valuations. Smaller family offices and those that don't specialize in tech startups more typically invest through a VC fund. One of the biggest trends in family offices is "co-investing," meaning a VC fund takes the lead on an investment and the family office invests as partners, often with lower fees.

Nico Mizrahi, co-founder and general partner of Pattern Ventures, which acts as a fund of funds for emerging managers and works with family offices, said there are growing risks for family offices trying to invest in tech startups on their own. After the stock market declines of 2022 and early 2023, which also brought down the valuations of many private tech companies, paper losses are piling up in the private tech market. The lack of IPOs, mergers and private-equity acquisitions has also made for fewer exits, locking up cash.

"Some of the family offices were not as disciplined and were drinking the Kool-Aid," Mizrahi said. "I think they over-extended themselves and got a little over eager chasing the venture wave. There are going to be some recaps; there are going to be companies that disappear."

Mizrahi said the best strategy, especially for smaller family offices, is to team up with experienced managers who have expertise in tech startups.

"It's really hard to get the best deals and generate the best returns when you're not doing something full time with 100% of your attention," he said. "You really have to do it with a partner, firms that are out there doing it all day long, networking and doing due diligence, background and reference checks."