Many experts agree that the art market is not transparent because most people are unaware of where to buy or sell fine art, since many art transactions happen privately between rather secretive buyers and sellers. Most former sales prices are seldom reported by auction houses, since they do not have to report sales prices. And the long-term nature of the investment may not allow for a known history of pricing on the art itself, since it may take decades before a particular piece is ever bought and sold.