After popping this week, CoreWeave shares are up about 65% since the company’s IPO earlier this year. Nvidia is a big beneficiary.

Nvidia owned nearly $900 million worth of shares in CoreWeave at the end of March, according to a filing from the chipmaker on Thursday. Assuming Nvidia hasn’t sold any shares since then, that stake is now worth close to $1.6 billion, as CoreWeave’s stock has surged in the past month.

CoreWeave shares gained 1.7% in after hours trading.

CoreWeave, which rents out access to Nvidia graphics processing units for training artificial intelligence models, went public on the Nasdaq in late March in the largest U.S. venture-backed tech IPO since 2021. Leading up to its debut, the company raised billions of dollars in debut and equity, including from key supplier Nvidia.

At the time of CoreWeave’s IPO prospectus, Nvidia owned 17.9 million shares shares for a stake worth around 5%. Nvidia now owns 24.2 million shares, Thursday’s filing shows.

As CoreWeave courted investors in its roadshow, the company issued an expected pricing range for the IPO of $47 to $55 per share. But the market was jittery after an extended IPO drought. Nvidia stepped in, offering to anchor the deal at $40 per share with a $250 million order, CNBC reported.

CoreWeave ultimately sold shares to investors at $40 each, raising $1.5 billion in the process. Mike Intrator, CoreWeave’s CEO, told CNBC just after the IPO that Nvidia is a “wonderful partner” and he called the relationship between the two companies “symbiotic.”

By Thursday, CoreWeave investors had seen substantial gains, with the stock closing at $65.77. The company late Wednesday reported 420% revenue growth from a year earlier, beating analysts’ estimates, a sign that the AI boom is continuing.