This is a monthly feature that runs down the month’s top 10 funding rounds in the U.S. Check out the biggest rounds of last month here.

May was a big month to raise, well, really big. Four rounds hit $1 billion or more and companies needed to raise at least $200 million to make this list. Not surprisingly AI led the way — as it always seems to do — with a trio of a billion-or-more rounds.

1. xAI, $6B, artificial intelligence: Elon Musk’s generative AI startup, xAI, officially announced its long-awaited fundraise — making it the second-most-valuable generative AI company in the world behind only competitor OpenAI. The $6 billion round included investment from the likes of Valor Equity Partners, Andreessen Horowitz, Sequoia Capital and Fidelity Management & Research, among others. The new funding values the company at $24 billion post-money, well behind OpenAI’s $86 billion valuation but well ahead of the $18 billion that fellow generative AI rival Anthropic is now valued at after its last raise. The xAI round had been rumored for months. Musk’s company was announced just last July and released its ChatGPT competitor, Grok, last November. It introduced its latest AI model, called Grok-1.5,  earlier this year. Grok is trained off data from another one of Musk’s companies, X, formerly Twitter.

2. CoreWeave, $1.1B, artificial intelligence: Another big AI-related funding round. AI cloud infrastructure startup CoreWeave locked up a $1.1 billion round led by Coatue that values the company at $19 billion, per The Wall Street Journal. The valuation represents an almost threefold increase from the company’s valuation just five months ago, when it was valued at $7 billion following a secondary sale, and a huge jump from its $2 billion valuation in a Series B extension last May. With the latest funding, the company has now raised some $4.6 billion, per Crunchbase data.

3. (tied) Scale AI, $1B, artificial intelligence: Are you sensing a trend this month with big AI rounds? Scale AI raised $1 billion in a round led by Accel that values the data labeling and evaluation startup at a stunning $13.8 billion. The valuation is nearly double the $7.3 billion the San Francisco-based startup hit after a $325 million raise in April 2021. The new financing included some of the biggest names in tech, with Nvidia, Meta and Amazon all investing. Scale AI plays a key role in creating large language models and accurately labeling text, images, video and voice data. The startup also creates and fine-tunes data sets.

3. (tied) Wiz, $1B, cybersecurity: Finally, something that is not AI. Cloud security startup Wiz locked up the biggest cybersecurity round of the year thus far as it raised $1 billion at a $12 billion valuation. The round — announced just as the industry’s RSA Conference was getting underway in San Francisco early last month — could be another sign of investors coming back to the cybersecurity space. Cyber startups are coming off their best funding quarter in three quarters, and in late April Microsoft-backed data security firm Rubrik had a successful IPO. Wiz’s latest round was co-led by Andreessen Horowitz, Lightspeed Venture Partners and Thrive Capital. Founded in 2020, Wiz says it has raised $1.9 billion so far. Originally founded in Israel, Wiz has been busy of late. In April, it acquired New York-based cloud detection and response startup Gem Security. The company says the new cash infusion could be used for more deal-making. Also based in New York, the startup says it achieved $350 million in annual recurring revenue last year. It has talked openly about hitting $1 billion in ARR as it heads to an IPO.

5. Motional, $475M, autonomous vehicles: Hyundai showed it is willing to spend big on Boston-based self-driving startup Motional. In May, the carmaker agreed to invest $475 million directly into the startup while also buying 11% of joint venture partner Aptiv’s equity stake in the company for another $448 million. Motional, formerly nuTonomy, was in the news just a couple of months ago for reportedly securing a bridge loan to extend its runway until another funding round. It seems like this situation bears watching.

6. Uniquity Bio, $300M, biotech: While AI dominated, biotech also saw some big rounds in May. The biggest in May was from a brand-new company launched by Blackstone Life Sciences — a unit of private equity giant Blackstone Group — along with a sizable $300 million investment. The new startup is a clinical-stage drug development company focused on immunology and inflammation. Uniquity already has FDA acceptance of its Phase 2 investigational new drug application for one of its medicines.

7. Vercel, $250M, developer platform: Vercel, a platform that allows companies to develop web applications in the cloud, locked up a $250 million Series E at a valuation of $3.25 billion. The round was led by Accel, with participation from other existing investors including CRV, GV, Notable Capital (previously GGV Capital), Bedrock, Geodesic Capital, Tiger Global, 8VC and SV Angel 1. The new round is an upround from Vercel’s 2021 raise, when it secured $150 million in a Series D funding at a $2.5 billion valuation led by GGV Capital. The San Francisco-based company allows developers to use an open-source framework to create web applications, and tries to simplify the process to migrate websites to cloud infrastructure to help with accessibility. Vercel has a number of big-name customers such as Under Armour, Unity and Nintendo. The company says it recently surpassed $100 million in annualized revenue and more than 1 million monthly active developers. Founded in 2015, the company has raised $568 million, per Crunchbase.

8. AltruBio, $225M, biotech: AltruBio secured a $225 million Series B led by BVF Partners. The San Francisco-based startup is developing therapeutics for the treatment of ulcerative colitis and other immunological diseases. The new cash will be used to support ongoing and planned Phase 2 clinical trials in ulcerative colitis. Founded in 2000, AltruBio has raised nearly $328 million, per Crunchbase.

9. (tied) BridgeBio Oncology Therapeutics, $200M, biotech: Biotech saw a big spinoff in May, as BridgeBio Pharma launched subsidiary BridgeBio Oncology Therapeutics as its own company with $200 million of new funding. The Palo Alto, California-based spinoff aims to grow its oncology portfolio. The financing was co-led by Cormorant Asset Management and Omega Funds.

9. (tied) Sigma, $200M, analytics: Cloud analytics startup Sigma raised a $200 million Series D co-led by Spark Capital and Avenir Growth Capital. Similar to Vercel, it was an upround from the company’s last financing. The San Francisco-based company says the valuation was a 60% increase from its $300 million Series C led by D1 Capital Partners and XN in 2021 and it was reported the new valuation was $1.5 billion. Founded in 2014, the company has raised $581 million, per Crunchbase.

9. (tied) Zenas BioPharma, $200M, biotech: Waltham, Massachusetts-based Zenas BioPharma raised a $200 million Series C preferred stock round led by Delos Capital, New Enterprise Associates, Norwest Venture Partners and SR One. The biotech firm specializes in inflammation- and immunology-directed therapies and will use the fresh cash to support the ongoing lead product candidate, obexelimab. Founded in 2020, the company has raised $318 million, per Crunchbase.

Big global deals

xAI and CoreWeave were the biggest raises of the month, but No. 3 came from the U.K.

• London-based self-driving car startup Wayve raised $1.05 billion in a SoftBank-led round.

Methodology

We tracked the largest rounds in the Crunchbase database that were raised by U.S.-based companies for the month of May 2024. Although most announced rounds are represented in the database, there could be a small time lag as some rounds are reported late in the month.

Illustration: Dom Guzman