Ownership structure changes, like capital concentration in funds, theoretically shouldn’t alter passive incentives, given fee competition and single-company engagement costs. Free rider problems also contribute to passivity. Despite these, recent factors boosting involvement include: (i) the influence of major investment funds, (ii) growing use of proxy advisors by institutional investors, (iii) political pressure and stewardship considerations, and (iv) collaboration, especially among hedge funds. ESG investing could be a game changer due to millennial demand, systemic risk reduction, and fee opportunities. This prompts institutional investors to shift from passive to active engagement, fostering collaboration. New collaboration forms include: (i) among major funds, (ii) between hedge and ESG funds (wolf pack activism), (iii) among non-activist institutional investors, and (iv) on new platforms like Climate Action100+ and PRI. Legal risks and obstacles, such as acting in concert, insider trading rules, and antitrust laws, are explored, with suggestions to enhance collaboration opportunities and ways of bolstering opportunities for collaboration.