Pan Sutong. Goldin Properties On Wednesday we brought you the story of Hanergy Thin Solar, formerly the world's largest solar-energy company, and its majority owner, Li Hejun, now the former richest man in China.

Having seen the value of the company soar in recent months, it all came crashing down Wednesday with shares in the company dropping by 47%. It lost Hejun, in paper form at least, about $15 billion.

You'd think a loss of the magnitude wouldn't be repeated anytime soon.

And you'd be wrong.

Earlier Thursday, shares in Goldin Property Holdings Limited, a Hong Kong-listed subsidiary of Goldin Group, collapsed, dropping a whopping 60% upon the resumption of trade. As recently as Wednesday, shares in the company traded as high as $HK29.50. At the lows Friday, $HK9.52, that equates to a net decline of 67.7%.

Goldin Financial Holdings Limited, also a subsidiary of Goldin Group, has also seen its value drop by 67% from Wednesday's highs to Thursday's lows.

Strangely, no announcement has been made by either company, and both continue to trade.

Goldin Property Holdings One-Year Chart

Whatever the reason behind the plunge, as was the case with Hanergy on Thursday, the decline has made the majority shareholder, billionaire Pan Sutong, significantly lighter in the pocket.

According to the latest filing with the Hong Kong Exchange, Pan owned about 65% of Goldin Property and over 70% in Goldin Financial.

Given the size of his holding and the subsequent decline in both companies' value, by Business Insider's calculations, this equates to a total two-day loss of about $HK160 billion, or just a smidge under $21 billion.

Chump change, hey?

The only question now is whose turn will it be tomorrow to see his paper wealth drop by a mind-boggling amount.