(Yicai Global) Dec. 14 -- Once the leader in China's mobile gaming industry, Ourpalm Technology Co.'s [SHE:300315] stock is in free-fall as investors dump shares and executives resign in groups and in quick succession.

Investors have sold more than CNY6 billion (USD908 million) worth of Ourpalm shares in two years as over a dozen executives have quit the Beijing-based firm, 21st Century Business Herald reported yesterday.

Former Chairman Yao Wenbin sold stock worth CNY2.35 billion before leaving in August last year, slashing his stake to just over 14 percent from almost 50 percent at the time of Ourpalm's listing in 2012. Second-largest shareholder Huayi Brothers Media Corp. [SHE:300027] sold CNY2.47 billion in stock, cutting its stake to just 0.42 percent.

Ourpalm went public on the cusp of an upsurge in the mobile gaming sector. The tech company pooled assets through a series of mergers and acquisitions and its market value reached CNY54 billion in 2015, prompting many stock-holding employees to sell and step down.

That set off a brain drain, which with increasingly fierce market competition, caused the share price to plummet. Its was worth CNY16.88 billion at market close on Dec. 12.

Deng Pan, who succeeded Yao, left with General Manager Hu Bin and Supervisor Sun Juanxia at the end of November, while Li Haosheng, deputy general manager and board secretary, announced his departure a month ago.