Shan reportedly told investors he had found a buyer for a stockpile of metals that could have bailed the exchange out and helped make payments to investors, but one investor, identified as Gu, told the Financial Times, “[Shan] was deceiving us. He admitted to us that there is no buyout group."

When the Fanya exchange froze its payments earlier this year, part of the issue was that investors expected to be able to retrieve their funds whenever they wanted. Quartz wrote at the time:

At issue is an investment called Ri Jin Bao, a financial product guaranteed by Fanya that promises retail investors annualized returns as high as 13.7%, and the right to withdraw funds at any time. Those funds have been frozen since April, when Fanya said it ran into “liquidity problems,” according to Caixin (link in Chinese).

The exchange trades in what are called minor metals—things like cobalt, titanium and tungsten which are not traded on major exchanges like the Shanghai Futures Exchange or the London Metal Exchange. They're mostly used in advanced electronic products (including some medical devices). According to industry news site Mining.com, China controlled the majority of the world's supply of these metals until 2010 when the government put limits on exports, which encouraged overseas minor metals markets to grow.

Update: This post was originally titled "Angry investors kidnap head of a Chinese stock exchange and deliver him to police as the market crashes"