From the viewpoint of an investor, what red flags existed in the Madoff case?

I am paying for 2 pages, but I only need 300 words max.

The paper must use Arial 12-point font, single spaced with one-inch margins on all sides. The response to the question must be between 200 – 300 words. Those limits include every word written other than the question itself, references and citations, and they are firm.