Sitting just off Central Park’s south-east corner, New York’s Pierre hotel enjoys distinction as one of the city’s centres for wealth and power. It was the venue for General Electric chief executive Jack Welch’s 1981 speech that laid out his vision of why companies should focus on shareholder value.

Last week, big hedge funds and people in the activist investor ecosystem gathered at the Pierre for an annual conference on how that value might be realised ahead of the new season of shareholder meetings. With the stock market slumping this year and the Covid-19 pandemic largely over, activism is perking up after months of limited action.

This year’s conference buzzed with talk about a subtle but significant change to the activism rule book. A September rule change at the US Securities and Exchange Commission has handed activists a new tool that companies fought for years to keep out of shareholders’ reach.