Australia’s largest pension fund on Thursday emerged as a 5.1% stakeholder in Pilbara Minerals after snapping up shares now worth A$558 million ($371 million) at a time of heightened interest in the country’s lithium miners.

The only shareholder with a larger stake in Pilbara Minerals is a subsidiary of Ganfeng Lithium Group, which owns 5.7%, according to LSEG data.

A stock exchange filing, required as AustralianSuper‘s stake now makes it a “substantial shareholder”, showed the A$300 billion fund had built its position since July, picking up more shares in September and October as Pilbara‘s share price dropped.

Lithium stocks have been battered as prices for hard rock lithium, or spodumene, have slumped 70% over the past year. Pilbara Minerals is the most shorted stock on the Australian Stock Exchange, ASX data shows, which has sent its shares down 21% over the past year.

However, buyers are betting the plunge in lithium prices will be short-lived as supply shortages for battery makers reemerge.

AustralianSuper declined to comment.

The pension giant has become a more activist investor, leading opposition to a high-profile $10.6 billion bid for Australia’s top power retailer Origin Energy.

Its move into Pilbara Minerals comes at the same time as mining magnates have snapped up stakes in takeover battles for some of Pilbara‘s rivals.

Gina Rinehart, Australia’s richest person, spoiled Albemarle’s ALB.N A$6.6 billion bid for Liontown Resources LTR.AX.

Pilbara‘s shares closed 2.3% higher on Thursday.

Reuters