Turns out the former Chinese billionaire whose solar company just imploded was shorting his own stock

It turns out the man presiding over the implosion of one of China's stock market darlings was on the right side of the trade.

Li Hejun, the Chairman of Hanergy Thin Film Solar Group Ltd, added to a short position in his own company's stock days before it collapsed, Bloomberg reports.

"Li bought 26.4 million Hanergy additional shares at an average of HK$7.28 each on May 18, according to two separate filings to Hong Kong Exchange on Friday. He also increased his short position to 7.71 percent of Hanergy's issued share capital from 5.81 percent on the same day," said the report.

The fall of Hanergy was the talk of China this week. The $39 billion solar company's shares rose 500% over the past year then were halted suddenly on Wednesday before they plummeted.

The only way to describe the evaporation of such wealth is to say that it was breathtaking. According to reports Li lost $15 billion in one hour when shares fell 47%. Shares were suspended with no explanation. Also, notably, Li was absent from a board meeting held earlier that day.

There has been suspicious movement in the stock before this week, and Li has never explained his short position in his own company.

What we do know is that:

• The FT pointed out that there has tended to be a huge surge in Hanergy's stock occurring almost exclusively in the last 10 minutes of the trading day.
• It sells most of its produces back to its parent company, Hanergy Holding Group.
• China's Caixin online newspaper reports that Hanergy Holding Groupused shares in the solar company to take out bank loans which, according to sources close to the company, it has since failed to repay.
  

None of this looks good for Li Hejun, especially since it seems like he saw this coming based on his own short position.