Taiwan's biggest IC substrate maker, Unimicron, crashed to a limit-down close after prosecutors raided it over suspected "origin washing," wiping out a huge chunk of its market value — bad for retail holders, but big funds are treating the drop as a buying chance.

• Investigators searched the company on Friday over claims it relabeled where its products were made, and panic selling followed on the next trading day.
• Trading nearly froze: barely any shares changed hands at the floor price while sell orders piled up unfilled.
• The pain spreads wide because Unimicron is a top-10 Taiwan stock and a core holding in many actively managed Taiwan ETFs.
• Foreign and local institutions bought the dip, arguing the issue sits in the older circuit-board business, not the high-margin AI substrate line that drives profits.
• A local brokerage was more cautious, warning that shipment delays or customer compensation claims could widen the damage later.

Outlook: Prosecutors have denied reports of a second raid, and analysts expect the stock to stabilize once the probe's scope is clear, with some calling any further slide a buying opportunity.