The combined market value of listed companies in Taiwan hit NT$13.38 trillion (US$418.12 billion) at the close of trading Friday.
The market value of listed companies was down NT$86.45 billion, or 0.64 percent, over the previous week, according to recent statistics compiled by the Taiwan Stock Exchange Company (TSEC).
One of the main reasons for the drop was attributed to the concern about stock market declines in the US.
The statistics also showed that excluding the automobile and electronics industries, the market value of listed companies in the top 20 major industries declined for the week.
The market value for listed companies in the electric appliance and cable industry moved down the most at 6.4 percent.
Meanwhile, the market value of listed companies in the transportation, construction and composite industries all showed declines of over 3 percent.
The weighted index, the key barometer of the Taiwan Stock Exchange, closed at 5,848.91 on Friday.
It closed with a decrease of 40.61 points, or 0.69 percent, over the previous Friday's close, on a combined turnover of NT$266.3 billion for the week.