Funny you make this thread, I randomly watched it last night too.
I think the movie was based around both Goldman Sachs and Lehman brothers in a way, as they were faced with similar situations and both acted accordingly in it's position to hedge early. Probably closer to Goldman Sachs as it seemed like they were embracing this and simply charged it to the game this time but ultimately knew they'd make out like bandits and recover to make even more money later (today).
I really enjoyed a lot of the dialogue in the movie. It's funny, if you've been around dudes who work on Wall Street, a lot of them have the kind of attitude Will and Seth have. Like when Will's driving with Seth on the Brooklyn Bridge (looked like to me?) and Seth is feeling shytty about losing his job and the bigger picture of what's about to happen, millions of people losing everything and Will's explanation for it. I thought it was pathetic but accurate to how a lot of these guys really feel. Moreover, when they're talking about their bosses salary, their bosses boss salary, how Will spends his salary (2.5 million and how it's never enough) and then Sam and John's final conversation with Sam saying "I need the money" as to why he's staying with the company.
What made that even more interesting was seeing Sam's wife at the end, at their home obviously, that she was now living in. They were obviously going through a divorce or already divorced and she got the house and he was paying out the ass for it, hence, his reasoning for "I need the money". Overall great film though, check it out.