Nelson Peltz, the billionaire activist investor, would have won a seat on the board of US chemicals giant DuPont in 2015 had it not been for the world’s largest passive investors.

Trian Fund Management, the multi-billion dollar hedge fund run by Peltz, had waged a two-year battle with DuPont over its high corporate expenses and disappointing financial performance. Peltz wanted a place at the boardroom table, but to have a chance of victory he needed to secure the backing of DuPont’s largest shareholders — BlackRock, Vanguard and State Street — which held 258 million shares between them at the time.