MediaTek just set an all-time revenue record, yet its shares have dropped sharply since late September — bad news for anyone who expected strong results to lift the stock.

• Q3 revenue hit a record and beat the company's own forecast, driven by shipments of flagship phone chips.
• The stock has still fallen about 16% from its late-September high, slipping again today.
• Foreign funds have been selling for days while small retail investors pile in, with tens of thousands buying the dip.
• The pressure comes from a US rival announcing aggressive long-term growth targets, raising fears MediaTek's custom AI chip orders get split away.
• Analysts say the custom AI chip market is growing too fast for real order-stealing yet, with first small shipments to a US customer due this quarter.

Outlook: Expect more choppy trading until custom AI chip shipments actually ramp, with the stock's quarterly average near NT$4,220 seen as the line to watch.