The debut feature film from director J.C. Chandor features Spacey as a senior investment bank executive facing his company's imminent ruin as its disastrous exposure to mortgage-backed securities emerges on the eve of the 2008 financial crisis.
Spacey stars alongside fellow Oscar winner Jeremy Irons, who plays the sinking bank's charismatic but unscrupulous chief executive; Demi Moore, who appears as its chief risk officer; and "The Da Vinci Code"'s Paul Bettany.
In the film's opening phase, Spacey's character is seen presiding over the abrupt firing of bank traders while also worrying about his aging dog's cancer. The scene with the dog helped make the figure more approachable, Spacey said.
"The truth is, and I think what we've tried to illuminate in the film is that in a lot of cases these are just regular people who have regular jobs, who aren't making gazillions of dollars and who had to follow orders," Spacey told reporters.
He added that he found it "fascinating to try to humanize ... the kind of person who'd been so dehumanized for so long."
Cast members said meeting bankers ahead of the movie helped make them less judgmental about the business - although Irons characterized the chief executive he plays as "an amoral man who just wanted to keep the ship afloat and would do anything to keep the ship afloat."
"The film to me is a tragedy," director Chandor said, featuring people "realizing that they've wasted a little bit of their lives, or a lot of their lives."
"Margin Call" is one of 16 movies competing for the Berlin festival's top Golden Bear honor, which will be awarded on Feb. 19.
The field combines familiar faces such as actor Ralph Fiennes, making his directorial debut next week with "Coriolanus," with lesser-known talents such as Mexico-based first-time director Paula Markovitch, who was presenting her movie "The Prize" on Friday.
