If it was my money I'd trade all of it, but it's not.
This man has been poor most of his life, so I don't want to recommend him anything that has even a slight chance of loss.
I don't know how much he won and how he's collecting it but he wants to invest $50k out of it in something where it will grow, and since he asked for my advice, I'd only recommend something that has no risk (almost) at all.
So yeah, treasury bonds sound like a good idea. I will also look into what others posted.
thanks.