Clinton Group's 1.3% stake flipped Stillwater's board; Sibanye paid $2.2B

Stillwater Mining, the only US producer of platinum and palladium, entered 2013 weakened by CEO Frank McAllister's overpayment for Peregrine Metals' gold and copper assets, a diversification away from its core Montana mines just as precious-metal prices fell. Clinton Group, a New York hedge fund with only 1.3% of the stock, nominated a rival board slate and argued management itself was the problem.

Stillwater offered four board seats hours before the vote; Clinton refused, saying a split board meant gridlock. Shareholders then elected Clinton's four nominees anyway, including former Montana governor Brian Schweitzer and mining executive Michael McMullen, after ISS recommended throwing out the entire incumbent board and Glass Lewis backed three dissidents.

McAllister retired within weeks and McMullen, one of the Clinton nominees, became CEO later in 2013. The rebuilt board refocused the company on its Montana platinum-group mines, and in 2017 South Africa's Sibanye Gold acquired Stillwater for $18 per share in cash, an aggregate enterprise value of $2.2 billion, advised by Jones Day.

Clinton nominees took four of eight seats, the CEO retired within weeks, and in 2017 Sibanye bought Stillwater for $18 a share in cash, a $2.2B deal

The Peregrine overpayment was a concrete, recent mistake the incumbents could not explain away.

Both proxy advisers sided against management, turning a 1.3% stake into a winning coalition of institutions.

Clinton's nominees had real mining and political credentials, answering the 'inexperienced dissidents' defense before it was made.

An activist doesn't need a big stake, only a better argument: 1.3% plus ISS and Glass Lewis support was enough to replace the people in charge.

Under McMullen, Stillwater concentrated on its Stillwater and East Boulder mines in Montana and became the western hemisphere's primary platinum-group producer. The Sibanye deal, completed in May 2017, gave Sibanye its US footprint; the combined company was renamed Sibanye-Stillwater and the mines remain its core US asset.