Taiwan stocks fell 2.65 percent in their worst single-day percentage loss in three weeks on Monday, joining regional bourses in sharp declines as weak US employment data heightened fears of a global recession. Market sentiment turned cautious after an over 2 percent drop on Wall Street and foreign selling of Taiwan stocks on Friday. The TAIEX index sank 205.49 points to close at 7,551.57, its biggest one-day percentage fall since a 3.57 percent drop on August 19.