During and after World War II enormous profits were made by persons selling rare goods like cigarettes, chocolate, coffee and butter on the black market.
In general, all companies selling weapons increase their profits when war starts.
Furthermore one can distinguish passive war profiteers from active war profiteers.
Passive war profiteers make profits of a war without influencing duration and outcome of a war.
Active war profiteers in addition to make profits by a war have a vital interest to start and prolong a war in order to make or increase their own profits.