Just going to make a minor point that OpenAI does not have $1b (and anyway, they don't spend most of their money on AI risk but generic AI research), they have only a pledge for $1b from Musk. I've asked them several times for their Form 990, which would show how much money they actually have, but their 2016 one is still unavailable.
I tried looking in the IRS Form 990 dataset on Amazon S3, specifically searching the text files for forms published in 2017 and 2016.
I found no match for (case-insensitive) openai (other than one organization that was clearly different, its name had openair in it). Searching (case-insensitive) "open ai" gave matches that all had "open air" or "open aid" in them. So, it seems like either they have a really weird legal name or their Form 990 has not yet been released. Googling didn't reveal any articles of incorporation or legal name.