Warning sign #24:

Madoff dismisses such skepticism. "Whoever tried to reverse-engineer, he didn't do a good job. If he did, these numbers would not be unusual."

Warning sign #25:

Curiously, he charges no fees for his money-management services.

Warning sign #26:

Nor does he take a cut of the 1.5% fees marketers like Fairfield Greenwich charge investors each year. Why not? "We're perfectly happy to just earn commissions on the trades," he says.

Don't Ask, Don't Tell [Barron's]