Shares fell yesterday following declines on Wall Street overnight, with technology stocks leading the drop.
The TAIEX lost 95.28 points, or 1.6 percent, to 5,972.06.
Once the index dropped below 6,000, it sparked more selling, particularly in widely held technology stocks, KGI Securities (中信證券) trader Bill Huang said.
Trading value fell slightly to NT$73.15 billion (US$2.2 billion) yesterday from Wednesday's NT$74.84 billion.
President Securities (統一證券) manager Maggie Chien said trading value wasn't low, and that this indicated investor interest in technology shares still remains present ahead of the fourth-quarter peak for electronics sales.
AU Optronics Corp (友達), the world's third-largest maker of thin-film-transistor liquid-crystal-displays by shipments, tumbled 5.1 percent to NT$41.3, as investors worried about panel price declines due to a supply glut.
Shares of Mitac International Corp (神達) were also unchanged at NT$48.0, following news that the company landed new orders for its navigation devices.
The local currency's further weakness against the US dollar continued to fuel concerns.
On the Taipei foreign exchange market, the NT dollar fell NT$0.047 to NT$33.135, the lowest since Nov. 11, on speculation that rising oil prices will reduce the country's trade surplus and dampen company earnings.
"Oil importers are in a rush to buy the dollar" because of Taiwan's narrowing trade surplus, said Pory Shih, a trader at Chang Hwa Commercial Bank (彰化銀行).