Shares of Taiwanese materials maker Taihong have dropped sharply after doubts emerged about the hype that drove them up, bad news for anyone who bought near the top.

• The stock had soared to a record in August on hopes its PTFE material could replace glass fibre cloth in circuit boards.
• Industry checks now say PTFE can only replace part of that market, not all of it, knocking the story down.
• August sales fell from both the prior month and a year earlier, missing expectations, and sales for the year so far are slightly lower than last year.
• The stock hit its daily limit down yesterday and kept sliding today, now more than 21% below its peak, with foreign investors dumping shares all week.
• The company's higher-grade PTFE board is still only in customer testing, with mass production not planned until 2027.

Outlook: Without new orders or a production timeline pulled forward, the stock likely stays under pressure as speculative buyers exit.