Taiwan's stock exchange and over-the-counter market are clamping down on four volatile stocks, which is bad news for short-term traders in those names.

• Tianhan, Xisheng, Shengyu and IET-KY all go under trading curbs from August 25 through August 31.
• Trades in these stocks will only be matched at set intervals instead of continuously, slowing everything down.
• Tianhan is the harshest case, with matching only every 25 minutes, and it is the second time this month it has been punished.
• Another 38 stocks, including shipping firm Wan Hai, were flagged as "watch" stocks for unusual price moves.

Outlook: The curbs lift after August 31, but any stock that keeps swinging wildly risks being pulled back in.