The price of any item (including residential real estate) is determined by the theory of ‘supply and demand.’ If many people are looking to buy an item and the supply of that item is limited, the price of that item increases.
The supply of homes for sale typically increases every spring. Putting your home on the market now, rather than waiting for increased competition in the spring, might make a lot of sense.
Buyers in the market during the winter are truly motivated purchasers and they want to buy now. With limited inventory currently available in most markets, sellers are in a great position to negotiate.