[tortasaur]

Impostor syndrome is when you see yourself as an impostor but are actually competent, not vice versa.

[jrumbut]

You overpromise when you fear that what you can actually deliver is inadequate.

Obviously imposter syndrome doesn't lead inevitably to ponzi schemes, but it's a possible maladaptive response to those feelings. Bernie Madoff was probably competent enough to be successful at a high level, I have no idea why he actually went off the rails but I can see how imposter syndrome could lead someone in that direction.