Winsway was quick to issue a message to shareholders noting that it knew of no reason for the erratic surge in the stock’s performance.

“The board confirms that there are no negotiations or agreements relating to intended acquisitions or realisations which are discloseable under Rule 13.23 of the Rules Governing the Listing of Securities on the Stock Exchange, neither is the board aware of any matter discloseable under the general obligation imposed by Rule 13..09 of the Listing Rules which is or may be of a price-sensitive nature,” the company said.

According to Bloomberg shares in Winsway gained as much as 22% to $HK1.56 at 11.49am local time, marking their biggest increase since the company was listed in October 2010.

Block trades of between 500,000 and 992,000 shares were also reported to have been completed.

In April, Chinese aluminum producer Aluminum Corporation of China announced it would purchase a 29.9% stake in Winsway for $HK2.39 billion.

In February, Winsway took over Canadian operator Grande Cache Coal in a $C1B deal.

Winsway is one of the largest buyers of Mongolian coking coal and one of the leading suppliers of imported coking coal to China.

The company’s business includes procurement, transportation, storage, processing and marketing of coking coal.