Taiwan stocks erased early gains and ended down 0.4 percent on Monday, dragged by machinary makers and chip makers, which fell 1.7 percent and 1.3 percent, respectively. The main TAIEX index dropped 32.76 points to 7,609.50, after opening up 0.2 percent. Electronics shares fell 0.5 percent, while financial shares lost 0.6 percent. The Taiwan dollar was up T$0.037 at T$29.088.