So, I got too keen to see this movie to wait for it to be released in the cinemas here, so I watched it online. And man, I'm glad I did!
I don't actually know a lot about the financial issues this film gets into - but I found that this didn't matter at all when watching Margin Call. I was already a massive fan of Zachary Quinto and Jeremy Irons, and they were both absolutely wonderful and convincing. However, one of the more involved performances was probably that of Kevin Spacey - and he was just brilliant. He really captured the desperate but resigned emotion running throughout the entire film.
While I might have been able to appreciate the film better if I DID know more about finances, I can confidently say that the film was just as brilliant for me, as what we need to know is basically described in the film anyway. The superb acting made this independent film completely worth it - I definitely recommend it :)