Valeant Pharmaceuticals and Pershing Square recently announced their decision to make a joint $290 million payment to settle litigation arising from alleged insider trading committed in 2014. See “Did Pershing Square and Valeant Violate Insider Trading, Antitrust or Tender Offer Rules in Their Pursuit of Allergan?” (May 2, 2014). Shareholders of Allergan claimed that Pershing Square illegally enriched itself by buying Allergan shares, and earning more than $2 billion in profits, with the knowledge that Valeant planned to initiate a bid for Allergan. Although Valeant ultimately failed in its takeover bid for Allergan, allegations of insider trading and other violations of securities laws have dogged both Valeant and Pershing Square for years. Some observers may be surprised that the insider trading claims against Pershing Square and Valeant were not dismissed. Arguably, the respondents did not technically commit insider trading because they acted without scienter – a key component of insider trading violations as traditionally understood. This article analyzes the Valeant-Pershing Square settlement, together with insights from practitioners with expertise in insider trading law, to help readers understand the settlement’s implications on insider trading law and takeaways for activist investors. For additional analysis of the evolution of insider trading law, see “HFLR Panel Identifies Best Practices for Avoiding Insider Trading Liability in the Aftermath of Martoma” (Jan. 18, 2018).