When SoftBank announced the first close of its Vision Fund this weekend — securing an initial commitment of $93 billion from investors including Apple, Qualcomm and Foxconn — it also quietly disclosed it had taken a stake in Nvidia.

Bloomberg is today reporting the size of that stake is $4 billion, for 4.9 percent of the company, which it says would make SoftBank the fourth largest investor in the chip maker.

Albeit, not necessarily for much longer: A line in the PR for the Vision Fund close on Saturday notes that the Vision Fund will have the right to acquire “certain investments already acquired (or agreed to be acquired)” by the SoftBank Group — with Nvidia being listed as one of those investments, along with a 24.99 percent stake in chip designer Arm (which SoftBank acquired last year for ~$31 billion). Although SoftBank of course retains its own ties to the Vision Fund and the fund’s investments.

A SoftBank spokesman declined to confirm the amount of its investment in Nvidia or to comment on Bloomberg’s report.

As we wrote recently, Nvidia’s GPUs have arguably become the bedrock underlying the current AI market explosion. And AI is one of the core areas of focus for SoftBank’s Vision Fund. Indeed, CEO Masayoshi Son set out his personal conviction earlier this year that the next 30 years will see the rise of superintelligent AI — saying this underpins his “hurry” to raise the ~$100 billion fund. So a chunky Nvidia investment meshes with his view of tomorrow’s world.

Even so, SoftBank has been spreading a lot of cash around lately. Other recent confirmed investments include $1.4 billion in Indian fintech unicorn Paytm; lead investor in virtual reality Improbable Worlds‘ $502 million raise; $5 billion in China’s Uber-killer Didi Chuxing; and a fresh $1.7 billion in global connectivity company OneWeb, after also investing $1 billion last year.

Some of these stakes may well move into the Vision Fund imminently, as the Nvidia stake and a chunk of ARM reportedly have. The fund has also been linked to a potential investment in WeWork, among others.

Son has previously said the mammoth Vision Fund won’t be a “typical fund” — and indeed, in size it’s unprecedented. But its modus operandi is intended to be hard to ignore too. “Most of our investments will range between 20 and 40 percent, making us the largest shareholder and board member, in a position to discuss strategy with the founders,” he told Bloomberg earlier this year.

So if money can buy superintelligent AI, it looks like Son is going to be the one to try and prove it.