"I give you $30 billion if you use it to buy $30 billion of stuff from me" doesn't sound like a very good investment. Is Nvidia expecting more back than it puts in? Enough more to make the deal profitable?
"I give you 30B$ worth of hardware that costs me <10B$ to make in exchange for 30B$ worth of shares in your company" would be a more accurate description.
Well, I won't pretend I know the answer :) . But I assume that a) they are partially betting on making a normal return on investment (i.e. OAI not crashing), b) they profit from running a huge expense/revenue cycle (a company making say a million of profit and having a billion revenue is favored better than the same but with only ten million revenue), and c) even if all goes wrong, it is still better to get back most of the investment even if not everything and zero profit, compared to a possibility of just losing it all like SoftBank or other investors.
In the end it's exchanging GPUs for OpenAI shares. It's not a non-trade, and in the current market Nvidia could really sell the stuff for cash. The marginal cost is very much sharply positive.
Or is it just to keep Nvidia from crashing?