Dealers have to understand the business side of the art world. They keep up with trends in the market and are knowledgeable about the style of art people want to buy. They figure out how much they should pay for a piece and then estimate the resale price. They are also often passionate and knowledgeable about art. Those who deal with contemporary art promote new artists, creating a market for the artists' works and securing financial success for themselves. The art world is subject to economic booms and bust just like any other market. Art dealers must be economically conscious in order to maintain their livelihoods. The mark ups of art work must be carefully monitored. If prices and profits are too large, then investments may be devalued should an overstock or economic downturn occur.