Taiwan's chipmaker UMC fell hard the day after hitting its daily limit up, a bad turn for its more than a million small shareholders.

• Foreign investors sold a huge block of UMC shares, the biggest dump of any Taiwan stock that day.
• UMC had jumped to its upper price limit the day before, so the reversal caught buyers off guard.
• The wider Taiwan market opened strong on TSMC and memory chip stocks, then swung more than 500 points and closed down.
• AI and display panel stocks drew heavy selling, dragging the index into the red.
• Foreign money still bought Taiwan stocks overall, just not UMC — other laptop and panel makers like Wistron, Innolux and Compal were also sold off.

Outlook: UMC and other second-tier chip and hardware names look shaky while foreign money rotates toward TSMC and memory.