What Does the Ending of American Psycho mean?

Can you explain the ending of the American Psycho movie?
This is one videotape we don’t want to return.

The ending of American Psycho can be explained in two different ways. While both explanations are valid, it is ultimately up to the viewer to decide what really happened throughout the movie.

Because the ending is so reliant on the plot, let me give you a quick summary of American Psycho.

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