Prosecutors raided Taiwan's biggest IC substrate maker, Unimicron, and the stock dropped sharply on the news — bad for shareholders in the near term.

• Taoyuan prosecutors and investigators searched Unimicron over suspected commercial fraud offences.
• The charge covers trademark and false labelling rules, and the suspicion is the company disguised where its products were made.
• Unimicron said it is cooperating fully, business is running normally, and there is no major hit to its finances.
• The stock sold off fast once word of the raid spread.

Outlook: The investigation will hang over the shares until prosecutors say more, even if operations stay unaffected.