Taiwan's stock market fell hard on Monday even as chipmaker UMC jumped 6% on heavy buying, a good day for UMC's shareholders but a bad one for the broader market.

• The Taiwan index opened up more than 100 points, then reversed and closed down 461 points, dropping below the 45,000 mark.
• Selling hit electronics, financial, and traditional industry stocks, pushing the index under its three-month average.
• UMC was the standout winner, briefly hitting its daily limit before easing back, with trading volume swelling.
• Local investment trusts were the big buyers, snapping up UMC in size, and foreign investors and dealers bought alongside them.
• Textile maker Far Eastern New Century and several mid-size electronics and financial names also drew fund buying.

Outlook: UMC has momentum from institutional money, but the index breaking a key support level points to more choppy trading ahead.