The series of Fanya inventory auctions by the Kunming Intermediate People's Court are being closely watched by minor metals traders, as well as creditors seeking the return of around 40 billion yuan following the collapse of the Yunnan-based exchange in 2015.
The bourse was later taken over by government investigators and its founder was jailed in March for 18 years for crimes including embezzlement.
In a day-long auction that ended in Beijing at 1015 (0215 GMT) on Sunday, Shanghai Sanqian New Energy Materials made the highest bid for the cobalt, which is currently in storage in Shanghai, according to the auction page on Taobao.
Even with China observing its National Day holiday from Oct. 1-7, the auction was a hotly contested affair with 143 bids, many submitted on Sunday morning.
The price paid works out at 281,262 yuan ($39,350.00) a tonne, above the current London Metal Exchange cobalt price of $34,000 a tonne, Reuters calculation showed. London cobalt was trading at more than $90,000 a tonne 18 months ago.
The starting price in the auction had been set at 3.92 million yuan, while the market value was put at 4.9 million yuan.
Six Fanya auctions so far, covering materials as varied as antimony and ammonium paratungstate (APT), have raised more than 4 billion yuan.
However, one Shanghai-based former investor in the exchange, who puts the total amount owed at around 43 billion yuan, said creditors "will not simply accept repayment only from the result of auctions".
"If there is any gap between the auction proceeds and our original investment, we will keep pushing the government to close the gap," the former investor said on condition of anonymity.
(Reporting by Hallie Gu, Huizhong Wu and Tom Daly; Editing by Christopher Cushing)