SEC Cracks Down on Activist Investor Secrecy

In a move that may rattle hedge funds, the Securities and Exchange Commission (SEC) has clarified its stance on 13D filings and proxy statements, requiring activist investors to disclose the identities of their clients in regulatory filings.

Source: s.yimg.com

The updated interpretations on 13D filings and proxy statements, issued by the main U.S. securities regulator, had not been expected and have not been widely reported, according to lawyers who work on investor activism. The SEC’s new guidance on its Corporate Finance Interpretations clarifies how the agency views its rules on critical filings after a busy six months of activist campaigns.

The regulator did not respond to a request for comment on the changes or say what prompted it to issue the interpretation now. However, the changes signal increased interest in transparency about what investors pushing for boardroom changes or other matters must say about their clients, the legal advisers said.

The changes come as special purpose vehicles called ‘sidecars’ are increasingly used to finance activist campaigns. According to the SEC, the identities of the investors in an entity formed for the purpose of acquiring securities of a specific issuer and engaging in an activism campaign at that issuer must be disclosed.

The answer to Question 155.02, which asks whether clients are considered ‘participants’ in a limited partnership that aims to solicit votes to change board directors, is ‘yes’ if these clients invested more than $500. This means that hedge funds will have to disclose the identities of their investors, which could potentially limit their ability to make money.

In the first half of 2026, investors including Elliott Investment Management, Ancora Alternatives, and TOMS Capital Investment Management have pushed companies ranging from media giant Warner Bros Discovery to Devon Energy to perform better. Hedge funds have long prized secrecy around the identity of their investors, arguing that identifying anything about their business could embolden copycats and limit their ability to make money.

However, companies targeted by corporate activists say greater transparency, including knowing who is invested, is necessary information to defend themselves. The SEC’s interpretation will remind companies and hedge funds of 2022, when medical device company Masimo Corp, facing a fight with Politan Capital, amended its bylaws to force any activist planning to nominate directors to disclose the identities of the fund’s limited partners and reveal future plans to nominate candidates elsewhere.

The Masimo bylaws sparked outrage among seasoned activist investors. While few companies followed Masimo’s lead, hundreds of corporations contacted their lawyers to ask whether they too should adopt such bylaws, attorneys said. In early 2023, Masimo reversed course and stopped requiring hedge funds to detail this information. In 2026, it was purchased by Danaher.

The changes signal a shift towards greater transparency in the world of activist investing. As hedge funds continue to rely on special purpose vehicles to finance their campaigns, the SEC’s updated guidance will require them to disclose the identities of their clients. This could potentially limit their ability to make money, but it also provides companies with the information they need to defend themselves against activist investors.