The Securities and Exchange Commission has issued new interpretive guidance requiring activist investors to identify the clients behind entities used in shareholder campaigns, the agency said in updated answers to its Corporate Finance Interpretations. The clarification applies to 13D filings and certain proxy statement questions and was released on Thursday.
Lawyers who work on investor activism said the guidance was not widely expected and noted it had not been broadly reported. Several of those lawyers spoke on condition of anonymity so they could discuss the topic more freely. The SEC did not respond to a request for comment on the interpretive updates and did not indicate what prompted the timing of the guidance.
The guidance explicitly addresses the identities of investors in vehicles formed to buy securities of a specific issuer and to engage in an activism campaign at that issuer. In its answer to Question 110.09 the SEC states that "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."
Another response, to Question 155.02, considers whether clients are "participants" in a limited partnership that seeks to solicit votes to change board directors. The SEC says the answer is "yes" where those clients have invested more than $500, reflecting the agency's view that such contributors meet the threshold for participation in certain disclosure contexts.
Legal advisers who reviewed the wording said the changes show the regulator is placing greater emphasis on transparency around who supports investors pressing for boardroom changes or other corporate actions. The issue has taken on greater prominence as so-called sidecars - special purpose vehicles that allow outside investors to back a campaign - have become more common ways to finance activist efforts.
Hedge funds and activist investors have long valued secrecy about the identities of those who provide capital for campaigns, arguing that revealing backers could encourage copycats and reduce returns. But the growing use of sidecars changes the dynamics, since potential investors in those vehicles are typically informed about the strategy and the name of the target company, enabling them to place capital into a specific corporate play rather than into a fund's broader portfolio.
Companies that face activist campaigns say that knowing who is invested in a vehicle pursuing board or operational changes is necessary to mount an adequate defense. The SEC's interpretive answers will likely rekindle attention to prior episodes in which disclosure and defensive measures were contested.
The guidance calls to mind a high-profile example from 2022 in which Masimo Corp, engaged in a fight with an activist, amended its bylaws to force any activist planning to nominate directors to reveal the identities of the fund's limited partners and to disclose any future plans to nominate candidates at other companies. That bylaw change generated strong pushback from experienced activist investors.
Although few companies adopted Masimo-style bylaws after the uproar, attorneys reported that hundreds of corporations reached out to counsel to ask whether they should consider similar measures. Masimo later reversed that specific disclosure requirement in early 2023. The company was acquired in 2026 by Danaher.
Over the first half of 2026, a range of activist investors, including Elliott Investment Management, Ancora Alternatives and TOMS Capital Investment Management, have sought to pressure companies to improve performance. Targets named by advisers included media giant Warner Bros Discovery and energy company Devon Energy, among others.
The SEC did not explain whether the uptick in activist activity over recent months influenced its decision to publish the interpretive answers, but the guidance arrives after a busy six months for activism according to the legal advisers consulted. For companies, investors and the advisers who counsel them, the guidance offers a clearer statement of the agency's expectations on disclosure when an entity is formed with the specific intent to engage in an activist campaign.
Background limitations - The SEC's updates are interpretive answers within its Corporate Finance guidance and do not include additional commentary from the agency explaining why the guidance was issued at this time.