The Thrift Savings Plan’s common stock (C) fund in 2001 posted the worst year since the fund’s inception in 1988, losing 11.94 percent for the calendar year after gaining 0.88 percent in December. The yearly loss comes as no surprise to investors who have been watching the fund’s struggles on a month-to-month basis-the fund was down in six of the 12 months, including four monthly drops exceeding 6 percent-but the decline still stings, especially following the drop of 9.14 percent in 2000, which until now was the worst annual performance in the fund’s history.