In 1993, Philip Morris, Inc. (PM) (defendant), made the decision to drastically lower the price of its best-selling cigarettes. At the time, the cigarette-manufacturing industry was oligopolistic, with five firms controlling 97 percent of the market. After PM lowered its prices, other cigarette manufacturers followed suit. As a result of the price competition, the profits for cigarette manufacturers decreased considerably. Eventually, PM began to increase the price of its cigarettes, and the other manufacturers again followed suit. The prices of cigarettes were raised several times between 1993 and 2000, and the manufacturers settled on roughly the same price increase each time. Williamson Oil Company, Inc., and other cigarette wholesalers (the wholesalers) (plaintiffs) brought a complaint against PM and several other manufacturers (defendants), alleging that the parallel price increases amounted to a price-fixing conspiracy. The district court granted the manufacturers’ motion for summary judgment, and the wholesalers appealed.