Macquarie Infrastructure v. Moab Partners -- a unanimous decision came down from our Supreme Court last week. The opinion, written by Justice Sotomayor, says in essence that securities fraud, regarded as an actionable private tort, is a tort of malfeasance, not of nonfeasance. Let us abstract from the particular facts a bit. Consider any case in which a plaintiff believes that he was sold stock by the issuing corporation at an unrealistically high price. He has sued. Asked why he bought it at such a price, the plaintiff might say, "They didn't tell me about X, a fact known to them and one that soon thereafter eliminated the value of the securities at issue." This decision tells that plaintiff: that isn't enough. You're going to have to plead, and in due course prove, that they made materially false statements, not simply that they failed to make certain true ones. The decision is a matter of interpreting the text of an SEC rule, 10b–5(b), which m...