Great piece in Slate by Ray Fisman on researchers who have found that stock prices of companies likely to benefit from CIA coups d'etat rose in advance of the event. Exhibit A: United Fruit Co. and the outrageous toppling of Guatemala's democratically elected government in the 1950s. The academics speculate that government insiders were buying up United Fruit shares, knowing that the company was soon to get its Guatemalan plantations back.

Such trading on inside information is illegal, and when it involves highly classified details about a future CIA coup, it verges on treason. Yet the researchers found that prices of companies affected by the CIA's regime-toppling efforts—UFC in Guatemala, Anglo-Iranian (oil) in Iran, Anaconda (mining) in Chile, and American Sugar in Cuba—went up in the weeks and months preceding the coups. (The authors restrict their analysis to coups for which they had access to declassified planning documents and for which U.S. companies had had property nationalized by the targeted regimes.)