In the standard supply and demand model, buyers are in equilibrium:
on the demand curve while sellers are in equilibrium on the supply curve. on the supply curve while sellers are in equilibrium on the demand curve. above the market-clearing price while sellers are in equilibrium below the market-clearing price. below the market-clearing price while sellers are in equilibrium above the market-clearing price.
A market with many buyers but only one seller has:
both a demand curve and a supply curve. neither a demand curve nor a supply curve. a supply curve but no demand curve. a demand curve but no supply curve.
