Goldman is apparently maintaining a position in Facebook, not just trading them back and forth between buyers and sellers. That's, I think, what Josh is getting at. I think you may only have read the first part of that description.
I did miss the requirement that GS would have to sell their position immediately to be a textbook moneymaker. And that does confirm Josh's frustration that there's people here with a rather casual understanding of the financial lingua. ;-)
Still, my assumption was that GS thinks it can make enough from potential deals to cover whatever risk there is that FB is not worth $50 billion.
