Investors in a Ponzi scheme have no recourse against the traders who executed its trades, according to the 5th U.S. Circuit Court of Appeals. The court ruled there was no allegation that the traders knew about the scheme, and the traders' failure to investigate whether it was a Ponzi scheme did not rise to the level of recklessness. Although it applies to a civil action, the ruling may limit criminal liability for traders similarly caught up in unwittingly helping Ponzi schemers.