 Shares of Weyerhaeuser Co. WY, -6.39 took 6.4 dive in afternoon trading, toward a 21-month low, after BofA Securities analyst George Staphos downgraded the paper and forest products company, citing a lower outlook for operating rates and pricing for wood products and a looming recession. Staphos cut his rating to neutral from overweight, and lowered his price target to 34 from 38. 