The most expensive red Bordeaux wines are frequently sold as futures. Under this system, customers buy the wine from retailers up to two years before it is actually released from the chateaux. The customers base their decisions (a gamble, really) on the reputation of the chateaux and on early assessments of the vintage.
Buying futures is, in effect, buying on speculation. In return for taking the risk and for paying cash in advance, these customers are assured of securing what is usually a highly sought after wine and they get to buy that wine at a price lower than the eventual release price.