Everyone knows that the suckers on the bottom of the pyramid lose when it collapses, enriching those on the top.

And even when it's spelled out that way, and there's no trickery or deceit, people still choose to play.

This particular game won't stop until there have been no transactions at all for seven days.  It could go on for a long time.

Is it morally right to play the game if you get in early, even when you know it's designed to eventually fail?