To an angry and unhappy investor, every deal that does not turn out as expected seems a private misfortune. For lawyers, the dispute that walks in to the door is analyzed, prepared, and tried on its individual merits. Yet large economic changes often explain why a category of disputes has arisen and help predict new rounds of litigation.

Unexplained price changes underlie some of the largest groups of oil and gas investor disputes in the last half century. In as volatile an industry as oil and gas, prices frequently ...