The U.S. Dollar Index (DXY) rose by 0.21% to 98.241 on December 31, reflecting heightened activity in the forex market. The euro declined to $1.1747 from $1.1767, while the British pound fell to $1.3466 from $1.3507. Meanwhile, the Japanese yen weakened to 156.49 per dollar, and the Swiss franc appreciated slightly to 0.7917 from 0.7896. As the dollar strengthens, traders are closely monitoring altcoin movements.