Fedweek

The three stock-oriented TSP funds in January gained back much of the ground they lost in December, with the small company stock S fund up 11.64 percent, the large company stock C fund up 8.01 percent and the international stock I fund up 6.6 percent for the month.

The bond F fund meanwhile gained 1.07 percent and the government securities G fund gained 0.23 percent. The returns, all gains, for the lifecycle L funds were: Income, 1.83; 2020, 2.53; 2030, 4.92; 2040, 5.86; 2050, 6.67. For last-12-month returns and TSP insight, visit https://www.fedweek.com/thrift-savings-plan/

Fundamentals like earnings-per-share, debt levels, and economic strength drive stock market prices in the long-term. But in the short-term, most trading is governed by emotional humans and trading algorithms, and they frequently pay attention to what charts look like.

When the market had a sudden drop in December, it crashed down through a significant support level that it had bounced off from twice before.
See also: Can the Stock Market Rally All the Way Back?