US Stock Market: SEC tightens disclosure rules for activist investors, raising transparency bar

The US SEC has tightened disclosure rules for activist investors through updated Corporate Finance Interpretations, requiring greater transparency in Schedule 13D filings and proxy statements. The guidance mandates disclosure of investors in special purpose vehicles used to finance activist campaigns, with clients investing more than $500 in such limited partnerships also considered participants. The move is expected to impact hedge funds like Elliott Investment Management and Ancora Alternatives, which have traditionally kept investor identities confidential, and could reshape how activist campaigns at companies such as Warner Bros. Discovery and Devon Energy are financed going forward.