Shares of Goldin Financial Holdings and Goldin Properties Holdings fell more than 55 percent in Hong Kong on Thursday, wiping a combined HK$177 billion ($22.83 billion) off the value of the companies owned by Hong Kong businessman Pan Sutong.
The dramatic plunge in the value of the companies follows that of Hanergy Thin Film Power Group Ltd, which on Wednesday dropped nearly 50 percent before being halted, with a source later telling Reuters the Chinese company is under investigation by Hong Kong's watchdog.
Both Goldin Financial and Hanergy had seen their values climb more than four-fold since September, prior to their stock price's collapse this week. Reuters could not immediately determine any link between the two companies beyond their similar patterns of share price movement.
Goldin Financial, which is 70 percent owned by Pan, saw its shares rise 411 percent between September last year and March this year.
The company's business includes factoring, a means of providing finance to small businesses secured against their sales, and ownership of vineyards in France and California.
On March 13, Hong Kong's Securities and Futures Commission cautioned investors on trading in Goldin Financial's shares, noting that just 20 investors including Pan between them own 98 percent of the shares.
The company has said it was not aware of a reason for the surge in its share price earlier this year. Neither shares of Goldin Financial nor those of Goldin Properties, of which Pan owns about 65 percent, were suspended from trading on Thursday morning, as often happens following unusual share price movements.