Funds run by Phillip Goldstein and Carl Icahn have been the most active participants in US shareholder campaigns started by hedge funds during the first half of this year, according to activism research firm FactSet SharkWatch.

Goldstein’s Bulldog Investors and Icahn Associates were each involved in six activist campaigns out of 262 in the six months to the end of June. FactSet SharkWatch defines an activist campaign as going beyond a simple shareholder proposal and publicly agitating for change at an organisation.