1. Competition, not competitors: the law protects the process — being outcompeted is lawful; being excluded is not.
2. Consumer welfare standard (and its contest): effects on price, quality, innovation.
3. Effect over form: agreements are judged by what they do, not what they are called.
4. Proportionality of intervention: remedy the harm, not the whole firm (the structural-versus- behavioural remedy debate).
5. Extraterritorial reach: effects doctrine — conduct abroad hitting the home market may be caught.