It is the beginning of the so-called Santa Claus rally.
Historically, the stock market has seen gains from the last five trading sessions of December through the first two trading days of January.
So far, markets are embracing the Christmas spirit, with all three major indices trading firmly in the green.
The tech-heavy Nasdaq led the way higher in late morning trading, up about 1%. Tesla (TSLA), Arm Holdings (ARM), and Broadcom (AVGO) posted the biggest gains within the index, with increases of 5%, 4%, and 3%, respectively.
Most sectors also traded in the green, with consumer discretionary (XLY), energy (XLE) and technology (XLK) being the three biggest gainers of the morning session. Healthcare (XLV) was the biggest laggard, dragged down by drugmaker Viatris (VTRS) and insurance company Cigna (CI).