The 30-year Treasury bond yield TMUBMUSD30Y, 1.454% traded at 0.84% on Monday, down 72 basis points over the last two sessions. That would mark the biggest back-to-back plunge for the long bond since Oct. 1987, the month when stocks experienced their biggest one-day percentage drop in history. Bond prices move in the opposite direction of yields. Fears that members of the Organization of Petroleum Exporting Countries and Russia would engage in a price war sent crude values to their biggest one-day slump since the Gulf War, and depressed inflation expectations. The 30-year bond is particularly sensitive to the direction of price pressures, as its fixed-interest payments can be corroded by inflation.