• Mack spent $672,000 buying 550,000 shares at 80.78 pence each
  • Glencore shares have rebounded since plunging 29% on Monday

John J. Mack, the former chief executive officer of Morgan Stanley, spent about $670,000 buying up Glencore Plc shares a day after they plunged by the most ever to a record low.

Mack, 70, who’s also a director of the Swiss commodity trader and miner, bought 550,000 shares at 80.78 pence each on Tuesday, according to a regulatory filing on Thursday. The stock slid 29 percent on Monday, before rebounding 33 percent in the following two days.

Glencore’s chairman and former BP Plc CEO Tony Hayward has also been buying stock in the company, which has had about $45 billion wiped off its market value this year and has sought to allay investors fears over its debt amid a rout in commodities. Hayward bought 100,000 shares priced at 91 pence each, according to a filing on Wednesday.

Mack was appointed an independent non-executive director of Glencore in June 2013. Since stepping down as chairman of Morgan Stanley at the end of 2011, he has served as an adviser to asset managers including KKR & Co. and BKM Capital Partners.

Peter Grauer, the chairman of Bloomberg LP, the parent of Bloomberg News, is a senior independent non-executive director at Glencore.

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