The price of any item (including residential real estate) is determined by ‘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.
According to the National Association of Realtors (NAR), the supply of homes for sale dramatically increases every spring. As an example, here is what happened to housing inventory at the beginning of 2017:
The #1 Reason to Sell Now Before Spring | MyKCM
Putting your home on the market now instead of waiting for increased competition in the spring might make a lot of sense.