On February 5, 2021, the Securities and Exchange Commission charged Oregon resident Mark Ahn with insider trading in the securities of Massachusetts-based pharmaceutical company Dimension Therapeutics, Inc. in advance of an August 2017 merger announcement.

The SEC's complaint, filed in federal district court in Massachusetts, charges Ahn with violating the antifraud provisions of Section 10(b) of the Securities Exchange Act of 1934 and Rule 10b-5 thereunder. The SEC seeks penalties, injunctive relief, and an order barring Ahn from serving as an officer or director of any SEC-reporting company.

In a parallel action, the U.S. Attorney's Office for the District of Massachusetts announced criminal charges against Ahn.

The SEC's case is being handled by Asita Obeyesekere, Nita Klunder, Xinyue Angela Lin, Sofia Hussain, Al Day, and Paul G. Block of the Boston Regional Office. The SEC appreciates the assistance of the U.S. Attorney's Office for the District of Massachusetts, the Federal Bureau of Investigation, and the Financial Industry Regulatory Authority.