When you are looking at listings daily and they go to Option Pending in a week or less, the buyers may outnumber the sellers.   Let me be clear though---this only applies if its a trend, certain houses will go quickly because they in the right location, priced correctly and in remarkable condition.  If you are looking regularly at specific neighborhoods, and homes are there one day and gone the next---it is a sellers market.   Home prices will go up when there arent enough homes for sale.  Note the market statistics on a month to month basis in your area, you should have a 6 month supply of inventory, when the numbers fall down to 3 months or less on available homes--A Sellers Market it is!