United States stock markets started the last week of the year with gains on Monday. The Omicron variant caused a sharp increase in the number of COVID-19 infections last week, with many flights canceled over the holiday weekend.

The Dow Jones added 0.19% at 9:30 am ET, led by Caterpillar Inc., which grew by 0.08%. The Nasdaq 100 increased by 0.39%, with Pinduoduo jumping 3.57%, and the S&P 500 gained 0.37% as Advanced Micro Devices improved by 2.61%.

The euro traded 0.06% higher compared to the dollar, going for 1.13194 at 9:31 am ET.